Polyphosphate fertilizer combinations

ABSTRACT

A composite particle and a population of particles comprising a water-insoluble polyphosphate composition, methods of producing, and methods of using the same are provided. The polyphosphate composition may comprise at least one alkaline earth metal selected from calcium and magnesium and optionally at least one nutrient ion selected from the group consisting of potassium, ammonium, zinc, iron, manganese, copper, boron, chlorine, iodine, molybdenum, selenium or sulfur.

FIELD OF THE INVENTION

The present invention generally relates to fertilizers and, inparticular, to composites comprising a polyphosphate fertilizercomposition.

BACKGROUND OF THE INVENTION

Phosphates are macronutrients generally thought to be essential buildingblocks for plants and animals. Plant fertilization with phosphates,alone or in combination with nitrogen and potash fertilization,generally results in better crop yields and more nutritious food.

Prior phosphate fertilizers include diammonium phosphate (DAP),monoammonium phosphate (MAP), triple super phosphate (TSP) and others.These water-soluble compounds, however, tend to leach from the soil,leading some to apply an amount that is several times the actual cropuptake, leading to poor efficiency and the contamination of waterbodies.

SUMMARY OF THE INVENTION

Among the various aspects of the present invention is the provision ofpopulations of particles comprising a water-insoluble, diluteacid-soluble polyphosphate composition having a defined size, theprovision of composite particles comprising a water-insoluble, diluteacid-soluble polyphosphate composition and at least one chemicallydistinct composition, the provision of fertilizer compositionscomprising such populations and/or composites, and the provision ofpolyphosphate fertilizers optionally containing at least one nutriention selected from the group consisting of potassium, sodium, ammonium,boron, chromium, cobalt, copper, iodine, iron, manganese, molybdenum,selenium, sulfur and zinc.

Briefly, the present invention is directed to a composite particlehaving a size greater than 80 mesh BS, the particle comprising awater-insoluble, dilute acid-soluble polyphosphate composition.

Briefly, the present invention is directed to a composite particlehaving a size greater than 0.2 mm, the particle comprising awater-insoluble, dilute acid-soluble polyphosphate composition.

Briefly, the present invention is directed to a composite particlehaving a size greater than 0.25 mm, the particle comprising awater-insoluble, dilute acid-soluble polyphosphate composition.

The present invention is further directed to a composite particle havinga size greater than 0.2 mm, the particle comprising a water-insoluble,dilute acid-soluble inorganic polyphosphate composition in solid form,the inorganic polyphosphate composition containing 5 to 70 wt %orthophosphate, and optionally one or more micronutrient metals selectedfrom the group consisting of chromium, cobalt, copper, iron, manganese,and zinc. The inorganic polyphosphate polymer has a number average chainlength of greater than 2 and less than 50 repeat units when theorthophosphate content of the inorganic polyphosphate polymer isexcluded from the average chain length calculation and a number averagechain length of at least 1.1 but less than 50 repeat units when theorthophosphate content of the inorganic polyphosphate polymer isincluded in the average chain length calculation, the repeat unitscomprising phosphate, sulfate, borate, molybdate, or selenate units, ora combination thereof, provided the ratio of phosphate units to thecombined total of sulfate, borate, molybdate and selenate repeat unitscomprised by the inorganic polyphosphate composition is at least 2:1.

The present invention is further directed to a composite particle havinga size greater than 0.2 mm, the particle comprising a water-insoluble,dilute acid-soluble inorganic polyphosphate composition in solid form,the inorganic polyphosphate composition containing ammonium, calcium,magnesium, sodium or potassium or a combination thereof, 5 to 70 wt %orthophosphate, and optionally one or more micronutrient metals selectedfrom the group consisting of chromium, cobalt, copper, iron, manganese,and zinc. The inorganic polyphosphate polymer composition has a numberaverage chain length of greater than 2 and less than 50 repeat unitswhen the orthophosphate content of the inorganic polyphosphate polymercomposition is excluded from the average chain length calculation and anumber average chain length of at least 1.1 but less than 50 repeatunits when the orthophosphate content of the inorganic polyphosphatepolymer composition is included in the average chain length calculation,the repeat units comprising phosphate, sulfate, borate, molybdate, orselenate units, or a combination thereof, provided the ratio ofphosphate units to the combined total of sulfate, borate, molybdate andselenate repeat units comprised by the inorganic polyphosphatecomposition is at least 2:1.

The present invention is further directed to a population of particleshaving an average size of greater than 80 mesh BS, the particlescomprising a water-insoluble, dilute acid-soluble polyphosphatecomposition.

The present invention is further directed to a population of particleshaving an average size of greater than 80 mesh BS, the particlescomprising a water-insoluble, dilute acid-soluble inorganicpolyphosphate composition in solid form, the inorganic polyphosphatecomposition containing 5 to 70 wt % orthophosphate, and optionally oneor more micronutrient metals selected from the group consisting ofchromium, cobalt, copper, iron, manganese, and zinc. The inorganicpolyphosphate polymer has a number average chain length of greater than2 and less than 50 repeat units when the orthophosphate content of theinorganic polyphosphate polymer is excluded from the average chainlength calculation and a number average chain length of at least 1.1 butless than 50 repeat units when the orthophosphate content of theinorganic polyphosphate polymer is included in the average chain lengthcalculation, the repeat units comprising phosphate, sulfate, borate,molybdate, or selenate units, or a combination thereof, provided theratio of phosphate units to the combined total of sulfate, borate,molybdate and selenate repeat units comprised by the inorganicpolyphosphate composition is at least 2:1.

The present invention is further directed to a population of particleshaving an average size of greater than 80 mesh BS, the particlescomprising a water-insoluble, dilute acid-soluble inorganicpolyphosphate composition in solid form, the inorganic polyphosphatecomposition containing ammonium, calcium, magnesium, sodium or potassiumor a combination thereof, 5 to 70 wt % orthophosphate, and optionallyone or more micronutrient metals selected from the group consisting ofchromium, cobalt, copper, iron, manganese, and zinc. The inorganicpolyphosphate polymer composition has a number average chain length ofgreater than 2 and less than 50 repeat units when the orthophosphatecontent of the inorganic polyphosphate polymer composition is excludedfrom the average chain length calculation and a number average chainlength of at least 1.1 but less than 50 repeat units when theorthophosphate content of the inorganic polyphosphate polymercomposition is included in the average chain length calculation, therepeat units comprising phosphate, sulfate, borate, molybdate, orselenate units, or a combination thereof, provided the ratio ofphosphate units to the combined total of sulfate, borate, molybdate andselenate repeat units comprised by the inorganic polyphosphatecomposition is at least 2:1.

The present invention is further directed to a population of particleshaving an average size of at least 0.25 mm, the particles comprising awater-insoluble, dilute acid-soluble polyphosphate composition.

The present invention is further directed to a population of particleshaving an average size of at least 0.2 mm, the particles comprising awater-insoluble, dilute acid-soluble inorganic polyphosphate compositionin solid form, the inorganic polyphosphate composition containing 5 to70 wt % orthophosphate, and optionally one or more micronutrient metalsselected from the group consisting of chromium, cobalt, copper, iron,manganese, and zinc. The inorganic polyphosphate polymer has a numberaverage chain length of greater than 2 and less than 50 repeat unitswhen the orthophosphate content of the inorganic polyphosphate polymeris excluded from the average chain length calculation and a numberaverage chain length of at least 1.1 but less than 50 repeat units whenthe orthophosphate content of the inorganic polyphosphate polymer isincluded in the average chain length calculation, the repeat unitscomprising phosphate, sulfate, borate, molybdate, or selenate units, ora combination thereof, provided the ratio of phosphate units to thecombined total of sulfate, borate, molybdate and selenate repeat unitscomprised by the inorganic polyphosphate composition is at least 2:1.

The present invention is further directed to a population of particleshaving an average size of at least 0.2 mm, the particles comprising awater-insoluble, dilute acid-soluble inorganic polyphosphate compositionin solid form, the inorganic polyphosphate composition containingammonium, calcium, magnesium, sodium or potassium or a combinationthereof, 5 to 70 wt % orthophosphate, and optionally one or moremicronutrient metals selected from the group consisting of chromium,cobalt, copper, iron, manganese, and zinc. The inorganic polyphosphatepolymer composition has a number average chain length of greater than 2and less than 50 repeat units when the orthophosphate content of theinorganic polyphosphate polymer composition is excluded from the averagechain length calculation and a number average chain length of at least1.1 but less than 50 repeat units when the orthophosphate content of theinorganic polyphosphate polymer composition is included in the averagechain length calculation, the repeat units comprising phosphate,sulfate, borate, molybdate, or selenate units, or a combination thereof,provided the ratio of phosphate units to the combined total of sulfate,borate, molybdate and selenate repeat units comprised by the inorganicpolyphosphate composition is at least 2:1.

The present invention is further directed to a population of particleshaving an average size of greater than 80 mesh BS, the particlescomprising at least 0.01 wt. % of a water-insoluble, dilute acid-solublepolyphosphate composition.

The present invention is further directed to a population of particleshaving an average size of greater than 80 mesh BS, the particlescomprising at least 0.01 wt. % of a water-insoluble, dilute acid-solubleinorganic polyphosphate composition in solid form, the inorganicpolyphosphate composition containing 5 to 70 wt % orthophosphate, andoptionally one or more micronutrient metals selected from the groupconsisting of chromium, cobalt, copper, iron, manganese, and zinc. Theinorganic polyphosphate polymer has a number average chain length ofgreater than 2 and less than 50 repeat units when the orthophosphatecontent of the inorganic polyphosphate polymer is excluded from theaverage chain length calculation and a number average chain length of atleast 1.1 but less than 50 repeat units when the orthophosphate contentof the inorganic polyphosphate polymer is included in the average chainlength calculation, the repeat units comprising phosphate, sulfate,borate, molybdate, or selenate units, or a combination thereof, providedthe ratio of phosphate units to the combined total of sulfate, borate,molybdate and selenate repeat units comprised by the inorganicpolyphosphate composition is at least 2:1.

The present invention is further directed to a population of particleshaving an average size of greater than 80 mesh BS, the particlescomprising at least 0.01 wt. % of a water-insoluble, dilute acid-solubleinorganic polyphosphate composition in solid form, the inorganicpolyphosphate composition containing ammonium, calcium, magnesium,sodium or potassium or a combination thereof, 5 to 70 wt %orthophosphate, and optionally one or more micronutrient metals selectedfrom the group consisting of chromium, cobalt, copper, iron, manganese,and zinc. The inorganic polyphosphate polymer composition has a numberaverage chain length of greater than 2 and less than 50 repeat unitswhen the orthophosphate content of the inorganic polyphosphate polymercomposition is excluded from the average chain length calculation and anumber average chain length of at least 1.1 but less than 50 repeatunits when the orthophosphate content of the inorganic polyphosphatepolymer composition is included in the average chain length calculation,the repeat units comprising phosphate, sulfate, borate, molybdate, orselenate units, or a combination thereof, provided the ratio ofphosphate units to the combined total of sulfate, borate, molybdate andselenate repeat units comprised by the inorganic polyphosphatecomposition is at least 2:1.

The present invention is further directed to a population of particleshaving an average size of at least 0.25 mm, the particles comprising atleast 0.01 wt. % of a water-insoluble, dilute acid-soluble polyphosphatecomposition.

The present invention is further directed to a population of particleshaving an average size of at least 0.2 mm, the particles comprising atleast 0.01 wt. % of a water-insoluble, dilute acid-soluble inorganicpolyphosphate composition in solid form, the inorganic polyphosphatecomposition containing 5 to 70 wt % orthophosphate, and optionally oneor more micronutrient metals selected from the group consisting ofchromium, cobalt, copper, iron, manganese, and zinc. The inorganicpolyphosphate polymer has a number average chain length of greater than2 and less than 50 repeat units when the orthophosphate content of theinorganic polyphosphate polymer is excluded from the average chainlength calculation and a number average chain length of at least 1.1 butless than 50 repeat units when the orthophosphate content of theinorganic polyphosphate polymer is included in the average chain lengthcalculation, the repeat units comprising phosphate, sulfate, borate,molybdate, or selenate units, or a combination thereof, provided theratio of phosphate units to the combined total of sulfate, borate,molybdate and selenate repeat units comprised by the inorganicpolyphosphate composition is at least 2:1.

The present invention is further directed to a population of particleshaving an average size of at least 0.2 mm, the particles comprising atleast 0.01 wt. % of a water-insoluble, dilute acid-soluble inorganicpolyphosphate composition in solid form, the inorganic polyphosphatecomposition containing ammonium, calcium, magnesium, sodium or potassiumor a combination thereof, 5 to 70 wt % orthophosphate, and optionallyone or more micronutrient metals selected from the group consisting ofchromium, cobalt, copper, iron, manganese, and zinc. The inorganicpolyphosphate polymer composition has a number average chain length ofgreater than 2 and less than 50 repeat units when the orthophosphatecontent of the inorganic polyphosphate polymer composition is excludedfrom the average chain length calculation and a number average chainlength of at least 1.1 but less than 50 repeat units when theorthophosphate content of the inorganic polyphosphate polymercomposition is included in the average chain length calculation, therepeat units comprising phosphate, sulfate, borate, molybdate, orselenate units, or a combination thereof, provided the ratio ofphosphate units to the combined total of sulfate, borate, molybdate andselenate repeat units comprised by the inorganic polyphosphatecomposition is at least 2:1.

Another aspect of the present invention is a population of particleshaving an average size of at least 0.2 mm comprising an inorganicpolyphosphate composition in solid form, characterized by having anX-ray diffraction reflection at one or more of the following positions:5.96 (±0.03), 5.37 (±0.03), 5.01 (±0.025), 4.73, 4.61, 4.5, 4.15, 4.04,3.7, 3.66(±0.01), 3.58(±0.01), 3.47(±0.01), 3.39(±0.01), 3.35(±0.01),3.19(±0.01), 3.13(±0.01), 3.09(±0.01), 3.05(±0.01), 2.96(±0.009),2.94(±0.009), 2.82(±0.009), 2.76(±0.008), 2.73(±0.008), 2.59(±0.007),2.53(±0.007), 2.5(±0.007), 2.43(±0.007), 2.41(±0.007), 2.37(±0.007),2.34(±0.006), 2.25(±0.006), 2.2(±0.006), 2.18(±0.005), 2.16(±0.005),2.14(±0.005), 2.12(±0.005), 2.09(±0.005), 2.08(±0.005), 2.03(±0.005),1.99(±0.004), 1.93(±0.004), 1.91(±0.004), 1.85(±0.003), 1.8(±0.003),1.76(±0.003), 1.72(±0.003), 1.68(±0.0028), 1.64(±0.0027), 1.59(±0.0025),1.57(±0.0024) Å.

Another aspect of the present invention is a population of particleshaving an average size of at least 0.2 mm comprising an inorganicpolyphosphate composition in solid form, characterized by having anX-ray diffraction reflection at one or more of the following positions:7.54(±0.03), 6.74(±0.03), 5.96 (±0.03), 5.37 (±0.03), 5.01 (±0.025),4.73, 4.61, 4.5, 4.15, 4.04, 3.7, 3.66(±0.01), 3.58(±0.01), 3.47(±0.01),3.39(±0.01), 3.35(±0.01), 3.19(±0.01), 3.13(±0.01), 3.09(±0.01),3.05(±0.01), 2.96(±0.009), 2.94(±0.009), 2.82(±0.009), 2.76(±0.008),2.73(±0.008), 2.59(±0.007), 2.53(±0.007), 2.5(±0.007), 2.43(±0.007),2.41(±0.007), 2.37(±0.007), 2.34(±0.006), 2.25(±0.006), 2.2(±0.006),2.18(±0.005), 2.16(±0.005), 2.14(±0.005), 2.12(±0.005), 2.09(±0.005),2.08(±0.005), 2.03(±0.005), 1.99(±0.004), 1.93(±0.004), 1.91(±0.004),1.85(±0.003), 1.8(±0.003), 1.76(±0.003), 1.72(±0.003), 1.68(±0.0028),1.64(±0.0027), 1.59(±0.0025), 1.57(±0.0024) Å.

Another aspect of the present invention is a population of particlescomprising an inorganic polyphosphate containing at least 5 wt. %calcium, magnesium, sodium, potassium or ammonium, in combination, andoptionally, one or more nutrients selected from boron, chromium, cobalt,copper, iodine, iron, manganese, molybdenum, selenium, and zinc, theinorganic polyphosphate composition having a solubility inroom-temperature (25° C.) deionized water such that the combined amountof ammonium, calcium, chromium, cobalt, copper, iron, magnesium,manganese, potassium, selenium, sodium, and zinc that dissolves from theinorganic polyphosphate composition during a 30 minute period indeionized water at room-temperature (25° C.) is less than 20% of thecombined amount of ammonium, calcium, chromium, cobalt, copper, iron,magnesium, manganese, potassium, selenium, sodium, and zinc thatdissolves from the inorganic polyphosphate composition during a 30minute period in 0.1N HCl at room-temperature (25° C.).

Another aspect of the present invention is a population of particlescomprising an inorganic polyphosphate containing at least 5 wt. % ofcalcium, magnesium, sodium, potassium or ammonium, in combination, andoptionally, one or more nutrients selected from boron, chromium, cobalt,copper, iodine, iron, manganese, molybdenum, selenium and zinc, theinorganic polyphosphate composition having a solubility inroom-temperature (25° C.) dilute citric acid such that the combinedamount of ammonium, calcium, chromium, cobalt, copper, iron, magnesium,manganese, potassium, selenium, sodium, and zinc that dissolves from theinorganic polyphosphate composition during a 20 minute period in citricacid having a citric acid concentration not in excess of 6.9 wt. %citric acid at room-temperature (25° C.) is at least 75% of the combinedamount of ammonium, calcium, chromium, cobalt, copper, iron, magnesium,manganese, potassium, selenium, sodium, and zinc that dissolves from theinorganic polyphosphate composition during a 20 minute period in 0.1NHCl at room-temperature (25° C.).

Another aspect of the present invention is a population of particlescomprising an inorganic polyphosphate containing at least 5 wt. % ofcalcium, magnesium, sodium, potassium or ammonium, in combination, andoptionally, one or more nutrients selected from boron, chromium, cobalt,copper, iodine, iron, manganese, molybdenum, selenium and zinc, theinorganic polyphosphate composition having a solubility inroom-temperature (25° C.) dilute citric acid such that the combinedamount of ammonium, calcium, chromium, cobalt, copper, iron, magnesium,manganese, potassium, selenium, sodium, and zinc that dissolves from theinorganic polyphosphate composition during a 20 minute period in citricacid having a citric acid concentration not in excess of 2 wt. % citricacid at room-temperature (25° C.) is at least 75% of the combined amountof ammonium, calcium, chromium, cobalt, copper, iron, magnesium,manganese, potassium, selenium, sodium, and zinc that dissolves from theinorganic polyphosphate composition during a 20 minute period in 0.1NHCl at room-temperature (25° C.).

Another aspect of the present invention is a population of particlescomprising an inorganic polyphosphate containing at least 5 wt. % ofcalcium, magnesium, sodium, potassium or ammonium, in combination, andoptionally, one or more nutrients selected from boron, chromium, cobalt,copper, iodine, iron, manganese, molybdenum, selenium and zinc, theinorganic polyphosphate composition having a solubility inroom-temperature (25° C.) dilute citric acid such that the combinedamount of ammonium, calcium, chromium, cobalt, copper, iron, magnesium,manganese, potassium, selenium, sodium, and zinc that dissolves from theinorganic polyphosphate composition during a 20 minute period in citricacid having a citric acid concentration not in excess of 0.1 wt. %citric acid at room-temperature (25° C.) is at least 75% of the combinedamount of ammonium, calcium, chromium, cobalt, copper, iron, magnesium,manganese, potassium, selenium, sodium, and zinc that dissolves from theinorganic polyphosphate composition during a 20 minute period in 0.1NHCl at room-temperature (25° C.).

Another aspect of the present invention is a population of particlescomprising an inorganic polyphosphate containing at least 5 wt. % ofcalcium, magnesium, sodium, potassium or ammonium, in combination, andoptionally, one or more nutrients selected from boron, chromium, cobalt,copper, iodine, iron, manganese, molybdenum, selenium and zinc, theinorganic polyphosphate composition having a solubility inroom-temperature (25° C.) dilute ethylenediaminetetraacetic acid (EDTA)such that the combined amount of ammonium, calcium, chromium, cobalt,copper, iron, magnesium, manganese, potassium, selenium, sodium, andzinc that dissolves from the inorganic polyphosphate composition duringa 20 minute period in 0.005M EDTA at room-temperature (25° C.) is atleast 75% of the combined amount of ammonium, calcium, chromium, cobalt,copper, iron, magnesium, manganese, potassium, selenium, sodium, andzinc that dissolves from the inorganic polyphosphate composition duringa 20 minute period in 0.1N HCl at room-temperature (25° C.).

Another aspect of the present invention is a population of particlescomprising an inorganic polyphosphate containing at least 5 wt. % ofcalcium, magnesium, sodium, potassium or ammonium, in combination, andoptionally, one or more nutrients selected from boron, chromium, cobalt,copper, iodine, iron, manganese, molybdenum, selenium and zinc, theinorganic polyphosphate composition having a solubility inroom-temperature (25° C.) dilute diethylenetriaminepentaacetic acid(DTPA) such that the combined amount of ammonium, calcium, chromium,cobalt, copper, iron, magnesium, manganese, potassium, selenium, sodium,and zinc that dissolves from the inorganic polyphosphate compositionduring a 20 minute period in 0.005M DTPA at room-temperature (25° C.) isat least 75% of the combined amount of ammonium, calcium, chromium,cobalt, copper, iron, magnesium, manganese, potassium, selenium, sodium,and zinc that dissolves from the inorganic polyphosphate compositionduring a 20 minute period in 0.1N HCl at room-temperature (25° C.).

Another aspect of the present invention is a population of particlescomprising an inorganic polyphosphate containing at least 5 wt. % ofcalcium, magnesium, sodium, potassium or ammonium, in combination, andoptionally, one or more nutrients selected from boron, chromium, cobalt,copper, iodine, iron, manganese, molybdenum, selenium and zinc, theinorganic polyphosphate composition having a solubility inroom-temperature (25° C.) dilute hydrochloric acid such that thecombined amount of ammonium, calcium, chromium, cobalt, copper, iron,magnesium, manganese, potassium, selenium, sodium, and zinc thatdissolves from the inorganic polyphosphate composition during a 20minute period in 0.01 N HCl at room-temperature (25° C.) is at least 75%of the combined amount of ammonium, calcium, chromium, cobalt, copper,iron, magnesium, manganese, potassium, selenium, sodium, and zinc thatdissolves from the inorganic polyphosphate composition during a 20minute period in 0.1N HCl at room-temperature (25° C.).

Another aspect of the present invention is a population of particlescomprising an inorganic polyphosphate containing at least 5 wt. % ofcalcium, magnesium, sodium, potassium or ammonium, in combination, andoptionally, one or more nutrients selected from boron, chromium, cobalt,copper, iodine, iron, manganese, molybdenum, selenium and zinc, theinorganic polyphosphate composition having a solubility inroom-temperature (25° C.) dilute citric acid, diluteethylenediaminetetraacetic acid (EDTA), dilutediethylenetriaminepentaacetic acid (DTPA) and dilute hydrochloric acidsuch that the combined amount of ammonium, calcium, chromium, cobalt,copper, iron, magnesium, manganese, potassium, selenium, sodium, andzinc that dissolves from the inorganic polyphosphate composition duringa 20 minute period in each of 0.1 wt. % citric acid, 0.005M EDTA and0.01 N HCl at room-temperature (25° C.) is at least 75% of the combinedamount of ammonium, calcium, chromium, cobalt, copper, iron, magnesium,manganese, potassium, selenium, sodium, and zinc that dissolves from theinorganic polyphosphate composition during a 20 minute period in 0.1NHCl at room-temperature (25° C.).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is generally directed to populations of particleshaving a defined size and comprising a water-insoluble, diluteacid-soluble polyphosphate composition and to composite particlescomprising a water-insoluble, dilute acid-soluble polyphosphatecomposition and at least one chemically distinct composition. In oneembodiment, the population of particles comprises the compositeparticles. In another embodiment, the population of particles comprisesparticles of a water-insoluble, dilute acid-soluble polyphosphatecomposition, optionally containing micronutrients. Thus, for example,the water-insoluble, dilute acid-soluble polyphosphate may be analkaline earth metal polyphosphate (as described in greater detailelsewhere herein) containing micronutrient amounts of a micronutrientselected from the group consisting of boron, chromium, cobalt, copper,iodine, iron, manganese, molybdenum, selenium, sulfur, zinc andcombinations thereof or a polyphosphate composition (as describedelsewhere herein) optionally containing such micronutrients. In oneembodiment, the water-insoluble, dilute acid-soluble polyphosphatecontains at least 5 wt. % alkali metal, alkaline earth metal, ammonium,or a combination thereof. In one embodiment, the water-insoluble, diluteacid-soluble polyphosphate contains at least 5 wt. % of calcium,magnesium, sodium, potassium or ammonium, in combination,

In general, the composite particles contain a water-insoluble, diluteacid-soluble polyphosphate composition and a chemically distinctcomposition. Within the composite particle, the chemically distinctcompositions may reside in discrete layers. For example, thewater-insoluble, dilute acid-soluble polyphosphate composition mayreside in a layer overlying the chemically distinct composition or in alayer underlying the chemically distinct composition. By way of furtherexample, the composite particles may comprise a core having a firstcomposition, and an outer layer over the core of a second, distinctcomposition; in this embodiment, the water-insoluble, diluteacid-soluble polyphosphate composition may reside in the core and thechemically distinct composition resides in the outer layer or viceversa. Alternatively, the water-insoluble, dilute acid-solublepolyphosphate composition and the chemically distinct composition arecombined in the particles without being segregated into discrete layers;for example, the water-insoluble, dilute acid-soluble polyphosphatecomposition and the chemically distinct composition may be combined byco-granulation or other technique to form particles having discontinuousregions of discrete composition.

In general, populations of particles of the present invention comprisinga water-insoluble, dilute acid-soluble polyphosphate composition have anaverage size of greater than 80 mesh BS. For example, in one embodiment,the population of particles has a size greater than 60 mesh BS. By wayof further example, in one embodiment the population of particles has anaverage size greater than 30 mesh BS. By way of further example, in oneembodiment the population of particles has an average size 16 mesh BS.By way of further example, in one embodiment the population of particleshas an average size greater than 10 mesh BS. By way of further example,in one embodiment the population of particles has an average sizegreater than 8 mesh BS. By way of further example, in one embodiment thepopulation of particles has an average size greater than 7 mesh BS. Byway of further example, in one embodiment the population of particleshas an average size greater than 6 mesh BS. By way of further example,in one embodiment the population of particles has an average sizegreater than 5 mesh BS. In each of the foregoing embodiments, thepopulation may comprise composite particles of the present invention, itmay comprise particles of the water-insoluble, dilute acid-solublepolyphosphate composition, per se, i.e., particles consisting of awater-insoluble, dilute acid-soluble polyphosphate composition, or acombination comprising the composite particles and the water-insoluble,dilute acid-soluble polyphosphate composition, per se.

In one embodiment, particles within the population of particles of thepresent invention comprise a water-insoluble, dilute acid-solublepolyphosphate composition and have a size of at least 0.2 mm (i.e., atleast one dimension of the particles is greater than 0.2 mm). Forexample, in one embodiment, the particles within the population have asize of at least 0.25 mm. By way of further example, in one embodimentthe particles within the population have a size of at least 0.35 mm. Byway of further example, in one embodiment the particles within thepopulation have a size of at least 0.5 mm. By way of further example, inone embodiment the particles within the population have a size of atleast 0.75 mm. By way of further example, in one embodiment theparticles within the population have a size of at least 1 mm. By way offurther example, in one embodiment the particles within the populationhave a size of at least 1.5 mm. By way of further example, in oneembodiment the particles within the population have a size of at least1.75 mm. By way of further example, in one embodiment the particleswithin the population have a size of at least 2 mm. By way of furtherexample, in one embodiment the particles within the population have asize of at least 2.5 mm. By way of further example, in one embodimentthe particles within the population have a size of at least 2.75 mm. Byway of further example, in one embodiment the particles within thepopulation have a size of at least 3 mm. By way of further example, inone embodiment the particles within the population have a size of atleast 3.25 mm.

In general, the composite particles have a size of greater than 80 meshBS. For example, in one embodiment, the particles have a size greaterthan 60 mesh BS. By way of further example, in one embodiment theparticles have a size greater than 30 mesh BS. By way of furtherexample, in one embodiment the particles have a size greater than 16mesh BS. By way of further example, in one embodiment the particles havea size greater than 10 mesh BS. By way of further example, in oneembodiment the particles have a size greater than 8 mesh BS. By way offurther example, in one embodiment the particles have a size greaterthan 7 mesh BS. By way of further example, in one embodiment theparticles have a size greater than 6 mesh BS. By way of further example,in one embodiment the particles have a size greater than 5 mesh BS.

The composite particles may be combined to form a population (or mass)of free-flowing particles having an average particle size greater than80 mesh. For example, in one embodiment, the population of particles hasan average particle size greater than 60 mesh BS. By way of furtherexample, in one embodiment the population of particles has an averageparticle size greater than 30 mesh BS. By way of further example, in oneembodiment the population of particles has an average particle sizegreater than 16 mesh BS. By way of further example, in one embodimentthe population of particles has an average particle size greater than 10mesh BS. By way of further example, in one embodiment the population ofparticles has an average particle size greater than 8 mesh BS. By way offurther example, in one embodiment the population of particles has anaverage particle size greater than 7 mesh BS. By way of further example,in one embodiment the population of particles has an average particlesize greater than 6 mesh BS. By way of further example, in oneembodiment the population of particles has an average particle sizegreater than 5 mesh BS.

In one embodiment, the composite particles have a size of at least 0.2mm (i.e., at least one dimension of the particles is greater than 0.2mm). For example, in one embodiment, the composite particles may have asize of at least 0.25 mm. By way of further example, in one embodimentthe composite particles have a size of at least 0.35 mm. By way offurther example, in one embodiment the composite particles have a sizeof at least 0.5 mm. By way of further example, in one embodiment thecomposite particles have a size of at least 0.75 mm. By way of furtherexample, in one embodiment the composite particles have a size of atleast 1 mm. By way of further example, in one embodiment the compositeparticles have a size of at least 1.5 mm. By way of further example, inone embodiment the composite particles have a size of at least 1.75 mm.By way of further example, in one embodiment the composite particleshave a size of at least 2 mm. By way of further example, in oneembodiment the composite particles have a size of at least 2.5 mm. Byway of further example, in one embodiment the composite particles have asize of at least 2.75 mm. By way of further example, in one embodimentthe composite particles have a size of at least 3 mm. By way of furtherexample, in one embodiment the composite particles have a size of atleast 3.25 mm.

In one embodiment, the composite particles are combined to form apopulation of particles having an average size of at least 0.2 mm (i.e.,at least one dimension of the particles is greater than 0.2 mm). Forexample, in one embodiment, the population of particles may have anaverage size of at least 0.25 mm. By way of further example, in oneembodiment the population of particles has an average size of at least0.35 mm. By way of further example, in one embodiment the population ofparticles has an average size of at least 0.5 mm. By way of furtherexample, in one embodiment the population of particles has an averagesize of at least 0.75 mm. By way of further example, in one embodimentthe population of particles has an average size of at least 1 mm. By wayof further example, in one embodiment the population of particles has anaverage size of at least 1.5 mm. By way of further example, in oneembodiment the population of particles has an average size of at least1.75 mm. By way of further example, in one embodiment the population ofparticles has an average size of at least 2 mm. By way of furtherexample, in one embodiment the population of particles has an averagesize of at least 2.5 mm. By way of further example, in one embodimentthe population of particles has an average size of at least 2.75 mm. Byway of further example, in one embodiment the population of particleshas an average size of at least 3 mm. By way of further example, in oneembodiment the population of particles has an average size of at least3.25 mm.

In general, populations of particles of the present invention compriseat least about 0.01% by weight of a polyphosphate polymer compositiondescribed herein. For example, in one embodiment the populationcomprises at least 0.05 wt. % of the polyphosphate composition. By wayof further example, in one embodiment the population comprises at least0.1 wt. % of the polyphosphate composition. By way of further example,in one embodiment the population comprises at least 0.25 wt. % of thepolyphosphate composition. By way of further example, in one embodimentthe population comprises at least 0.5 wt. % of the polyphosphatecomposition. By way of further example, in one embodiment the populationcomprises at least 0.75 wt. % of the polyphosphate composition. By wayof further example, in one embodiment the population comprises at least1 wt. % of the polyphosphate composition. Typically, however, thepopulation comprises will comprise less than 99 wt. % of thepolyphosphate composition. For example, in some embodiments, thepopulation comprises less than 90 wt. % of the polyphosphatecomposition. For example, in some embodiments, the population comprisesless than 80 wt. % of the polyphosphate composition. For example, insome embodiments, the population comprises less than 70 wt. % of thepolyphosphate composition. For example, in some embodiments, thepopulation comprises less than 60 wt. % of the polyphosphatecomposition. By way of further example, in some embodiments thepopulation comprises less than 50 wt. % of the polyphosphatecomposition. By way of further example, in some embodiments thepopulation comprises less than 40 wt. % of the polyphosphatecomposition. By way of further example, in some embodiments thepopulation comprises less than 30 wt. % of the polyphosphatecomposition. By way of further example, in some embodiments thepopulation comprises less than 20 wt. % of the polyphosphatecomposition. In certain embodiments, therefore, the population comprisesabout 0.01 to about 99 wt. % of the polyphosphate composition. Incertain embodiments, the population comprises about 0.01 to about 75 wt.% of the polyphosphate composition. In certain embodiments, thepopulation comprises about 0.01 to about 50 wt. % of the polyphosphatecomposition. In certain embodiments, the population comprises about 0.1to about 99 wt. % of the polyphosphate composition. In certainembodiments, the population comprises about 0.1 to about 75 wt. % of thepolyphosphate composition. In certain embodiments, the populationcomprises about 0.1 to about 50 wt. % of the polyphosphate composition.In certain embodiments, the population comprises about 1 to about 99 wt.% of the polyphosphate composition. In certain embodiments, thepopulation comprises about 1 to about 95 wt. % of the polyphosphatecomposition. In certain embodiments, therefore, the population comprisesabout 1 to about 75 wt. % of the polyphosphate composition. In certainembodiments, therefore, the population comprises about 1 to about 99 wt% of the polyphosphate composition. In certain embodiments, therefore,the population comprises about 0.5 to about 20 wt. % of thepolyphosphate composition. In certain embodiments, therefore, thepopulation comprises about 0.5 to about 15 wt. % of the polyphosphatecomposition. In certain embodiments, therefore, the population comprisesabout 0.5 to about 10 wt. % of the polyphosphate composition.

In general, the composite particles comprise at least about 0.01% byweight of a polyphosphate polymer composition described herein. Forexample, in one embodiment the composite particles comprise at least0.05 wt. % of a polyphosphate composition. By way of further example, inone embodiment the composite particles comprise at least 0.1 wt. % of apolyphosphate composition. By way of further example, in one embodimentthe composite particles comprise at least 0.25 wt. % of a polyphosphatecomposition. By way of further example, in one embodiment the compositeparticles comprise at least 0.5 wt. % of a polyphosphate composition. Byway of further example, in one embodiment the composite particlescomprise at least 0.75 wt. % of a polyphosphate composition. By way offurther example, in one embodiment the composite particles comprise atleast 1 wt. % of a polyphosphate composition. Typically, however, thecomposite particles will comprise less than 99 wt. % of a polyphosphatecomposition. For example, in some embodiments, the composite particlescomprise less than 90 wt. % of a polyphosphate composition. For example,in some embodiments, the composite particles comprise less than 80 wt. %of a polyphosphate composition. For example, in some embodiments, thecomposite particles comprise less than 70 wt. % of a polyphosphatecomposition. For example, in some embodiments, the composite particlescomprise less than 60 wt. % of a polyphosphate composition. By way offurther example, in some embodiments the composite particles compriseless than 50 wt. % of a polyphosphate composition. By way of furtherexample, in some embodiments the composite particles comprise less than40 wt. % of a polyphosphate composition. By way of further example, insome embodiments the composite particles comprise less than 30 wt. % ofa polyphosphate composition. By way of further example, in someembodiments the composite particles comprise less than 20 wt. % of apolyphosphate composition. In certain embodiments, therefore, thecomposite particles comprise about 0.01 to about 99 wt. % of apolyphosphate composition. In certain embodiments, the compositeparticles comprise about 0.01 to about 75 wt. % of a polyphosphatecomposition. In certain embodiments, the composite particles compriseabout 0.01 to about 50 wt. % of a polyphosphate composition. In certainembodiments, the composite particles comprise about 0.1 to about 99 wt.% of a polyphosphate composition. In certain embodiments, the compositeparticles comprise about 0.1 to about 75 wt. % of a polyphosphatecomposition. In certain embodiments, the composite particles compriseabout 0.1 to about 50 wt. % of a polyphosphate composition. In certainembodiments, the composite particles comprise about 1 to about 99 wt. %of a polyphosphate composition. In certain embodiments, the compositeparticles comprise about 1 to about 95 wt. % of a polyphosphatecomposition. In certain embodiments, therefore, the composite particlescomprise about 1 to about 75 wt. % of a polyphosphate composition. Incertain embodiments, therefore, the composite particles comprise about 1to about 99 wt. % of a polyphosphate composition. In certainembodiments, therefore, the composite particles comprise about 0.5 toabout 20 wt. % of a polyphosphate composition. In certain embodiments,therefore, the composite particles comprise about 0.5 to about 15 wt. %of a polyphosphate composition. In certain embodiments, therefore, thecomposite particles comprise about 0.5 to about 10 wt. % of apolyphosphate composition.

In addition to the polyphosphate composition described herein, thecomposite particles may comprise a nitrogen-source, a phosphoroussource, a potassium-source, a secondary or micronutrient source.Exemplary nitrogen sources include urea, ammonium sulfate and derivatiesthereof. Exemplary phosphorus sources include single superphosphates,triple superphosphates, calcium phosphates, nitrophosphates, potassiumphosphates, ammonium phosphates, ammoniated superphosphates and the likeand mixtures thereof. Exemplary potassium sources include muriate ofpotash, potassium sulfates, potassium phosphates, potassium hydroxides,potassium nitrates, potassium carbonates and bicarbonates, potassiummagnesium sulfates and the like and mixtures thereof. Suitable secondarynutrient sources for use herein include elemental sulfur, calcium andmagnesium salts such as phosphates, oxides, sulfates, carbonates,chlorides, nitrates and the like and mixtures thereof. Suitablemicronutrient sources include iron, manganese, copper, boron, zinc andmolybdenum salts such as phosphates, oxides, sulfates, carbonates,chlorides, nitrates, borates, molybdates and the like and mixturesthereof as well as chelates of micronutrients such as EDTA chelates andthe like. For example, the following representative materials may beused as micronutrient sources in the present invention: calcium nitrate,magnesium sulfate, magnesium nitrate, ferrous sulfate, ferrous nitrate,manganese sulfate, manganese nitrate, copper sulfate, copper nitrate,boric acid, sodium borate, zinc sulfate, zinc nitrate, sodium molybdate,ammonium molybdate and the like. For example, in such embodiments, thecomposite particles may also comprise in addition to the nitrogen,phosphorous, potassium, secondary or micronutrient source about 0.01 toabout 75 wt. % of a polyphosphate composition. By way of furtherexample, in such embodiments, the composite particles may also comprisein addition to the nitrogen, phosphorous, potassium, secondary ormicronutrient source about 0.01 to about 50 wt. % of a polyphosphatecomposition. By way of further example, in such embodiments, thecomposite particles may also comprise in addition to the nitrogen,phosphorous, potassium, secondary or micronutrient source about 0.01 toabout 25 wt. % of a polyphosphate composition. By way of furtherexample, in such embodiments, the composite particles may also comprisein addition to the nitrogen, phosphorous, potassium, secondary ormicronutrient source about 0.1 to about 25 wt. % of a polyphosphatecomposition. By way of further example, in such embodiments, thecomposite particles may also comprise in addition to the nitrogen,phosphorous, potassium, secondary or micronutrient source about 0.5 toabout 25 wt. % of a polyphosphate composition. By way of furtherexample, in such embodiments, the composite particles may also comprisein addition to the nitrogen, phosphorous, potassium, secondary ormicronutrient source about 0.5 to about 10 wt. % of a polyphosphatecomposition.

In another embodiment, the composite particles comprise a pesticide. Thepesticide may be, for example, a herbicide, insecticide, fungicide, orcombination thereof. Non-limiting examples of pesticides include 2-4D,parathion, malation, and s-triazines. For example, in such embodiments,the composite particles may also comprise in addition to the pesticideabout 0.01 to about 75 wt. % of a polyphosphate composition describedherein. By way of further example, in such embodiments, the compositeparticles may also comprise in addition to the pesticide about 0.01 toabout 50 wt. % of a polyphosphate composition. By way of furtherexample, in such embodiments, the composite particles may also comprisein addition to the pesticide about 0.01 to about 25 wt. % of apolyphosphate composition. By way of further example, in suchembodiments, the composite particles may also comprise in addition tothe pesticide about 0.1 to about 25 wt. % of a polyphosphatecomposition. By way of further example, in such embodiments, thecomposite particles may also comprise in addition to the pesticide about0.5 to about 25 wt. % of a polyphosphate composition. By way of furtherexample, in such embodiments, the composite particles may also comprisein addition to the pesticide about 0.5 to about 10 wt. % of apolyphosphate composition.

In one embodiment, the composite particles contain agrichemicals such asmanure, gypsum, dolomite, and plant growth hormones. For example, insuch embodiments, the composite particles may also comprise in additionto the agrichemicals about 0.01 to about 95 wt. % of a polyphosphatecomposition described herein. By way of further example, in suchembodiments, the composite particles may also comprise in addition tothe agrichemicals about 20 to about 95 wt. % of a polyphosphatecomposition. By way of further example, in such embodiments, thecomposite particles may also comprise in addition to the agrichemicalsabout 40 to about 95 wt. % of a polyphosphate composition. By way offurther example, in such embodiments, the composite particles may alsocomprise in addition to the agrichemicals about 50 to about 95 wt. % ofa polyphosphate composition. By way of further example, in suchembodiments, the composite particles may also comprise in addition tothe agrichemicals about 60 to about 95 wt. % of a polyphosphatecomposition. By way of further example, in such embodiments, thecomposite particles may also comprise in addition to the agrichemicalsabout 60 to about 95 wt. % of a polyphosphate composition.

In one embodiment, the composite particles contain granules of amacronutrient fertilizer, granules of china clay, bentonite,attapulgite, organic wastes, agricultural wastes having a size greaterthan 0.5 mm. In one embodiment, such particles have a size greater than1 mm. In another embodiment, such particles have a size greater than 2mm. In another embodiment, such particles have a size greater than 3 mm.Additionally, in such embodiments, the composite particles may alsocomprise about 10 to about 95 wt. % of a polyphosphate compositiondescribed herein. By way of further example, in such embodiments, thecomposite particles may also comprise about 30 to about 95 wt. % of apolyphosphate composition. By way of further example, in suchembodiments, the composite particles may also comprise about 40 to about95 wt. % of a polyphosphate composition. By way of further example, insuch embodiments, the composite particles may also comprise about 50 toabout 95 wt. % of a polyphosphate composition. By way of furtherexample, in such embodiments, the composite particles may also compriseabout 60 to about 95 wt. % of a polyphosphate composition. By way offurther example, in such embodiments, the composite particles may alsocomprise about 60 to about 95 wt. % of a polyphosphate composition.

In one embodiment, the composite particles comprise plant seeds. Forexample, the composite particles may comprise soybean, corn, rice orwheat seeds. Alternatively, the composite particles may comprise seedsof a plant other than soybean, corn, rice and wheat. Regardless of thetype of seed, in such embodiments, the composite particles may alsocomprise in addition to one or more seeds about 0.01 to about 75 wt. %of a polyphosphate composition described herein. By way of furtherexample, in such embodiments, the composite particles may also comprisein addition to one or more seeds about 0.01 to about 50 wt. % of apolyphosphate composition. By way of further example, in suchembodiments, the composite particles may also comprise in addition toone or more seeds about 0.01 to about 25 wt. % of a polyphosphatecomposition. By way of further example, in such embodiments, thecomposite particles may also comprise in addition to one or more seedsabout 0.1 to about 25 wt. % of a polyphosphate composition. By way offurther example, in such embodiments, the composite particles may alsocomprise in addition to one or more seeds about 0.5 to about 25 wt.% ofa polyphosphate composition. By way of further example, in suchembodiments, the composite particles may also comprise in addition toone or more seeds about 0.5 to about 10 wt. % of a polyphosphatecomposition.

In another embodiment, the composite particles comprise Al₂O₃, ZnO, aniron oxide, MnO₂, FeTiO₃, MgAl₂O₄, (ZnFeMn)(FeMn)₂O₄, quarry fines, adredge material, kaolin, glass, foundry sand, red mud, silica fines,coal fines, mine tailings, bauxite, recycled concrete, recovereddrywall, brucite, manganite, gibbsite, diaspare, bachmite, goethite,carnallite, boracite, epsomite, newberryite, magnasite, olivine,dolomite, metal slag, calcium-containing dredge containing an oxideand/or carbonate of calcium, agricultural fiber, ocean sand, ash,collected particles from metal processes involving combustion, a wastemetal slurry, a metal slurry, a metal shaving, graphite, or recycledasphalt. Regardless of the type of material, in such embodiments, thecomposite particles may also comprise in addition to one or more ofabove materials, about 0.01 to about 95 wt. % of a polyphosphatecomposition described herein. By way of further example, in suchembodiments, the composite particles may also comprise about 10 to about95 wt. % of a polyphosphate composition. By way of further example, insuch embodiments, the composite particles may also comprise about 30 toabout 95 wt. % of a polyphosphate composition. By way of furtherexample, in such embodiments, the composite particles may also compriseabout 40 to about 95 wt. % of a polyphosphate composition. By way offurther example, in such embodiments, the composite particles may alsocomprise about 50 to about 95 wt. % of a polyphosphate composition. Byway of further example, in such embodiments, the composite particles mayalso comprise about 60 to about 95 wt. % of a polyphosphate composition.By way of further example, in such embodiments, the composite particlesmay also comprise about 0.5 to about 10 wt. % of a polyphosphatecomposition.

In a preferred embodiment, the composite particles are formed bycombining a mass of a polyphosphate composition described herein havingan average size of less than 80 mesh BS with a mass of particles havingan average particle size greater than 80 mesh BS and mixing until alayer of the polyphosphate composition is formed on the surface of themass of larger particles or the polyphosphate particles adhere to thesurface of the larger particles. For example, in one embodiment a massof polyphosphate particles having an average particle size less than 80mesh BS are adhered to the surface of particles having an averageparticle greater than 80 mesh. Without wishing to be bound by anyparticular theory, and based upon experimental evidence obtainedto-date, it appears that this occurs as a result of electrostaticattraction of opposite charges or difference in acidity between thesurfaces of the smaller polyphosphate and the larger particles. Toexploit this, the polyphosphates may be synthesized to facilitate thisadsorption by adjusting the pH of the polyphosphate during synthesis.For example, if a polyphosphate is to be adsorbed to the surface of aparticle that is alkaline, such as urea (which has an alkaline surface),the polyphosphate preferably has a pH of less than 5, preferably in therange of pH 4 to 5 (the pH may be controlled, for example, bycontrolling the extent of neutralization during synthesis of thepolyphosphate). If, however, the polyphosphate is to be adsorbed to thesurface of a particle that is acidic, such as monoammonium phosphate(MAP) (which has an acidic surface), the polyphosphate preferably has apH of at least 5, preferably in the range of pH 5 to 7. Using suchtechniques, the amount of polyphosphate adsorbed to the surface of thelarger particle be 80 wt % or even more of the mass of the largerparticle. For example, in one embodiment, a mass of polyphosphateparticles having an average particle size of less than 150 mesh is mixedwith a mass of particles having an average particle size greater than0.5 mm until a layer of the polyphosphate composition is formed on themass of larger particles. By way of further example, in one embodiment,a mass of polyphosphate particles having an average particle size ofless than 150 mesh is mixed with a mass of particles having an averageparticle size greater than 1.5 mm until a layer of the polyphosphatecomposition is formed on the mass of larger particles. By way of furtherexample, in one embodiment, a mass of polyphosphate particles having anaverage particle size of less than 150 mesh is mixed with a mass ofparticles having an average particle size greater than 2 mm until alayer of the polyphosphate composition is formed on the mass of largerparticles. By way of further example, in one embodiment, a mass ofpolyphosphate particles having an average particle size of less than 150mesh is mixed with a mass of particles having an average particle sizegreater than 3 mm until a layer of the polyphosphate composition isformed on the mass of larger particles.

In one exemplary embodiment, the composite particles are formed bycombining a mass of a polyphosphate composition described herein havingan average size of less than 80 mesh BS with a mass of particles havingan average particle size greater than 80 mesh BS, mixing, moistening themixture with water and drying until a layer of the polyphosphatecomposition is formed on the surface of the mass of larger particles.For example, in one embodiment, a mass of polyphosphate particles havingan average particle size of less than 150 mesh is mixed with a mass ofparticles such as monoammonium phosphate, diammonium phosphate, triplesuper phosphate, single superphosphate, or combinations thereof, havingan average particle size greater than 0.5 mm, moistened with water anddried until a layer of the polyphosphate composition is formed on themass of larger particles. In another embodiment, a mass of polyphosphateparticles having an average particle size of less than 150 mesh is mixedwith a mass of particles having an average particle size greater than 1mm, moistened with water and dried until a layer of the polyphosphatecomposition is formed on the mass of larger particles. In anotherembodiment, a mass of polyphosphate particles having an average particlesize of less than 150 mesh is mixed with a mass of particles having anaverage particle size greater than 2 mm, moistened with water and drieduntil a layer of the polyphosphate composition is formed on the mass oflarger particles. In another embodiment, a mass of polyphosphateparticles having an average particle size of less than 150 mesh is mixedwith a mass of particles having an average particle size greater than 3mm, moistened with water and dried until a layer of the polyphosphatecomposition is formed on the mass of larger particles.

In one exemplary embodiment, a population of particles having an averagesize of greater than 80 mesh is formed by granulating smaller particlesof the polyphosphate composition (i.e., having a size of less than 80mesh) with or without a binder. For example, in one embodiment, a massof polyphosphate particles having an average particle size of less than80 mesh, is mixed with water, granulated in a granulator and dried untilan average particle size greater than 0.25 mm is formed. Alternatively,granulation is done with the suspension of the polyphosphate after itssynthesis and prior to it being dried. To enable granulation without theuse of a binder, the polyphosphate has a pH below 5 and preferably inthe range of pH 4 to 5. Inclusion of ammonium ion in the polyphosphate(by the use of ammonia during neutralization) improves granule strength.

In an alternative embodiment, the composite particles are formed byco-granulating the polyphosphate composition described herein with anyof the other materials disclosed herein using conventional granulationtechniques. In this embodiment, the polyphosphate composition mayfunction as a binder. For example, in one such embodiment, the compositeparticles are formed by combining a mass of a polyphosphate compositiondescribed herein having an average size of less than 80 mesh BS with amass of particles having an average particle size either less than 80mesh BS or greater than 80 mesh BS or both (such as muriate of potashfines, urea, or any of the other chemically distinct materials describedherein for combination with the polyphosphate composition), mixing,moistening the mixture with water, granulating in a granulator anddrying until a composite mass of larger particles is formed. Typically,binding is enhanced when the polyphosphate has a pH below 5 and whenammonium is incorporated in the polyphosphate. Without wishing to bebound to any particular theory and based upon experimental evidenceobtained to-date, it appears that ammonium improves hydrogen bondingbetween the particles and thereby improves adhesive strength.

In each of the granulation methods described herein, conventionalbinders may be included in the granulation step to enhance the bindingof the polyphosphate particles to other particles. Exemplary bindersinclude bentonite, starch, cellulose and its derivatives, polyvinylacetates, polyvinyl acetate copolymers, polyvinyl alcohols, polyvinylalcohol copolymers, celluloses, including ethylcelluloses andmethylcelluloses, hydroxymethyl celluloses, hydroxypropylcelluloses,hydroxymethylpropyl-celluloses, polyvinylpyrolidones, dextrins,malto-dextrins, polysaccharides, fats, oils, proteins, gum arabics,shellacs, vinylidene chloride, vinylidene chloride copolymers, calciumlignosulfonates, acrylic copolymers, starches, polyvinylacrylates,zeins, gelatin, carboxymethylcellulose, chitosan, polyethylene oxide,acrylimide polymers and copolymers, polyhydroxyethyl acrylate,methylacrylimide monomers, alginate, ethylcellulose, polychloroprene andsyrups or mixtures thereof. Other suitable binders include polymers andcopolymers of vinyl acetate, methyl cellulose, vinylidene chloride,acrylic, cellulose, polyvinylpyrrolidone and polysaccharide. Still othersuitable binders include polymers and copolymers of vinylidene chlorideand vinyl acetate-ethylene copolymers. Conventional granulationtechniques are followed.

Polyphosphate Compositions

The composite particles and populations of composite particles describedherein comprise water-insoluble, dilute acid-soluble inorganicpolyphosphate compositions. In general, the polyphosphate compositioncomprises ammonium, calcium, magnesium, sodium, potassium or acombination thereof and, optionally, at least one micronutrient (alsosometimes referred to herein as nutrients or nutrient ions) selectedfrom among ammonium, boron, chromium, cobalt, copper, iodine, iron,manganese, molybdenum, potassium, selenium, sodium, sulfur, zinc, andcombinations thereof. For example, in one embodiment the polyphosphatecomposition comprises calcium, magnesium or a combination thereof and,optionally, at least one micronutrient (also sometimes referred toherein as nutrients or nutrient ions) selected from among ammonium,boron, chromium, cobalt, copper, iodine, iron, manganese, molybdenum,potassium, selenium, sodium, sulfur, zinc, and combinations thereof.

In general, the inorganic polyphosphate compositions are relativelyshort-chain polyphosphates produced by incomplete polymerization oforthophosphates. Typically, therefore, the inorganic polyphosphate willcontain at least about 5 wt. % orthophosphate. Although the inorganicpolyphosphate may contain as much as 70 wt. % orthophosphate, it isgenerally preferred that the inorganic polyphosphate comprisesubstantially less. Thus, for example, in one embodiment the inorganicpolyphosphate may contain 5 to 50 wt. % orthophosphate. By way offurther example, in one embodiment the inorganic polyphosphate maycontain 7.5 to 50 wt. % orthophosphate. By way of further example, inone embodiment the inorganic polyphosphate may contain 10 to 45 wt. %orthophosphate. By way of further example, in some embodiments, theinorganic polyphosphate may contain 7.5 to 30 wt. % orthophosphate. Byway of further example, in some embodiments, the inorganic polyphosphatemay contain 10 to 30 wt. % orthophosphate. By way of further example, insome embodiments, the inorganic polyphosphate may contain 15 to 30 wt. %orthophosphate. By way of further example, in some embodiments, theinorganic polyphosphate may contain 10 to 25 wt. % orthophosphate. Byway of further example, in some embodiments, the inorganic polyphosphatemay contain 15 to 25 wt. % orthophosphate.

The inorganic polyphosphate compositions contain phosphate repeat unitsand may optionally also contain sulfate, borate, molybdate or selenaterepeat units, or a combination thereof. Typically, the ratio ofphosphate repeat units to the combined total of sulfate, borate,molybdate and selenate repeat units in the inorganic polyphosphatecomposition is at least 2:1(phosphate:sulfate+borate+molybdate+selenate). For example, in certainembodiments, the ratio of phosphate repeat units to the combined totalof sulfate, borate, molybdate and selenate repeat units in the inorganicpolyphosphate composition is at least 2.5:1. By way of further example,in some embodiments the ratio of phosphate repeat units to the combinedtotal of sulfate, borate, molybdate and selenate repeat units in theinorganic polyphosphate composition is at least 3:1. By way of furtherexample, in some embodiments the ratio of phosphate repeat units to thecombined total of sulfate, borate, molybdate and selenate repeat unitsin the inorganic polyphosphate composition will be between 2:1 and 5:1.By way of further example, in some embodiments the ratio of phosphaterepeat units to the combined total of sulfate, borate, molybdate andselenate repeat units in the inorganic polyphosphate composition will bebetween 2:1 and 10:1. By way of further example, in some embodiments theratio of phosphate repeat units to the sulfate repeat units in theinorganic polyphosphate composition will be between 2:1 and 5:1. By wayof further example, in some embodiments the ratio of phosphate repeatunits to the sulfate repeat units in the inorganic polyphosphatecomposition will be between 2:1 and 10:1.

Depending upon the extent of polymerization, the inorganicpolyphosphates may have a range of chain lengths. When the calculationis based upon total phosphate content (i.e., including theorthophosphate content of the polyphosphate), the average chain length(number average) may be in the range of about 1.1 to 50 repeat units(phosphate, sulfate, borate, molybdate and/or selenate repeat units) perchain. For example, in one embodiment the average chain length (numberaverage) may be 1.2 to 50 repeat units (phosphate, sulfate, borate,molybdate and/or selenate repeat units) per chain based upon totalphosphate content. By way of further example, in one embodiment theaverage chain length (number average) may be 1.2 to 25 repeat units(phosphate, sulfate, borate, molybdate and/or selenate repeat units) perchain based upon total phosphate content. By way of further example, inone embodiment the average chain length (number average) may be 1.2 to20 repeat units (phosphate, sulfate, borate, molybdate and/or selenaterepeat units) per chain based upon total phosphate content. By way offurther example, in one embodiment the average chain length (numberaverage) may be 1.2 to 15 repeat units (phosphate, sulfate, borate,molybdate and/or selenate repeat units) per chain based upon totalphosphate content. By way of further example, in one embodiment theaverage chain length (number average) may be 2 to 20 repeat units(phosphate, sulfate, borate, molybdate and/or selenate repeat units) perchain based upon total phosphate content. By way of further example, inone embodiment the average chain length (number average) may be 2 to 15repeat units (phosphate, sulfate, borate, molybdate and/or selenaterepeat units) per chain based upon total phosphate content. By way offurther example, in one embodiment the average chain length (numberaverage) may be 2 to 10 repeat units (phosphate, sulfate, borate,molybdate and/or selenate repeat units) per chain based upon totalphosphate content. By way of further example, in one embodiment theaverage chain length (number average) may be 2.5 to 15 repeat units(phosphate, sulfate, borate, molybdate and/or selenate repeat units) perchain based upon total phosphate content. By way of further example, inone embodiment the average chain length (number average) may be 2.5 to10 repeat units (phosphate, sulfate, borate, molybdate and/or selenaterepeat units) per chain based upon total phosphate content. By way offurther example, in one embodiment the average chain length (numberaverage) may be 3 to 15 repeat units (phosphate, sulfate, borate,molybdate and/or selenate repeat units) per chain based upon totalphosphate content. By way of further example, in one embodiment theaverage chain length (number average) may be 3 to 10 repeat units(phosphate, sulfate, borate, molybdate and/or selenate repeat units) perchain based upon total phosphate content. By way of further example, inone embodiment the average chain length (number average) may be 1.2 to 5repeat units (phosphate, sulfate, borate, molybdate and/or selenaterepeat units) per chain based upon total phosphate content. By way offurther example, in one embodiment the average chain length (numberaverage) may be 1.3 to 4 repeat units (phosphate, sulfate, borate,molybdate and/or selenate repeat units) per chain based upon totalphosphate content. By way of further example, in one embodiment theaverage chain length (number average) may be 1.3 to 2.9 repeat units(phosphate, sulfate, borate, molybdate and/or selenate repeat units) perchain based upon total phosphate content.

In certain embodiments, when the calculation is based upon totalphosphate content (i.e., including the orthophosphate content of thepolyphosphate), the average chain length (number average) may be in therange of about 1.2 and 50 phosphate units (phosphorus atoms) per chain.For example, in one embodiment the average chain length (number average)may be 1.2 to 25 phosphate units (phosphorus atoms) per chain based upontotal phosphate content. By way of further example, in one embodimentthe average chain length (number average) may be 1.2 to 20 phosphateunits (phosphorus atoms) per chain based upon total phosphate content.By way of further example, in one embodiment the average chain length(number average) may be 1.2 to 15 phosphate units (phosphorus atoms) perchain based upon total phosphate content. By way of further example, inone embodiment the average chain length (number average) may be 2 to 20phosphate units (phosphorus atoms) per chain based upon total phosphatecontent. By way of further example, in one embodiment the average chainlength (number average) may be 2 to 15 phosphate units (phosphorusatoms) per chain based upon total phosphate content. By way of furtherexample, in one embodiment the average chain length (number average) maybe 2 to 10 phosphate units (phosphorus atoms) per chain based upon totalphosphate content. By way of further example, in one embodiment theaverage chain length (number average) may be 2.5 to 15 phosphate units(phosphorus atoms) per chain based upon total phosphate content. By wayof further example, in one embodiment the average chain length (numberaverage) may be 2.5 to 10 phosphate units (phosphorus atoms) per chainbased upon total phosphate content. By way of further example, in oneembodiment the average chain length (number average) may be 3 to 15phosphate units (phosphorus atoms) per chain based upon total phosphatecontent. By way of further example, in one embodiment the average chainlength (number average) may be 3 to 10 phosphate units (phosphorusatoms) per chain based upon total phosphate content. By way of furtherexample, in one embodiment the average chain length (number average) maybe 1.1 to 5 phosphate units (phosphorus atoms) per chain based upontotal phosphate content. By way of further example, in one embodimentthe average chain length (number average) may be 1.2 to 5 phosphateunits (phosphorus atoms) per chain based upon total phosphate content.By way of further example, in one embodiment the average chain length(number average) may be 1.3 to 4 phosphate units (phosphorus atoms) perchain based upon total phosphate content. By way of further example, inone embodiment the average chain length (number average) may be 1.3 to2.9 phosphate units (phosphorus atoms) per chain based upon totalphosphate content.

When the calculation is based upon the non-orthophosphate fraction ofthe polyphosphate, (i.e., excluding the orthophosphate fraction of thepolyphosphate from the calculation), the average chain length (numberaverage) may be in the range of about 2 and the average chain length(number average) may be in the range of about 1.2 and 50 repeat units(phosphate, sulfate, borate, molybdate and/or selenate repeat units) perchain based upon the non-orthophosphate fraction of the polyphosphate.For example, in one embodiment the average chain length (number average)may be 1.2 to 25 repeat units (phosphate, sulfate, borate, molybdateand/or selenate repeat units) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe 1.2 to 20 repeat units (phosphate, sulfate, borate, molybdate and/orselenate repeat units) per chain based upon the non-orthophosphatefraction of the polyphosphate. By way of further example, in oneembodiment the average chain length (number average) may be 1.2 to 15repeat units (phosphate, sulfate, borate, molybdate and/or selenaterepeat units) per chain based upon the non-orthophosphate fraction ofthe polyphosphate. By way of further example, in one embodiment theaverage chain length (number average) may be 2 to 20 repeat units(phosphate, sulfate, borate, molybdate and/or selenate repeat units) perchain based upon the non-orthophosphate fraction of the polyphosphate.By way of further example, in one embodiment the average chain length(number average) may be 2 to 15 repeat units (phosphate, sulfate,borate, molybdate and/or selenate repeat units) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe 2 to 10 repeat units (phosphate, sulfate, borate, molybdate and/orselenate repeat units) per chain based upon the non-orthophosphatefraction of the polyphosphate. By way of further example, in oneembodiment the average chain length (number average) may be 2.5 to 15repeat units (phosphate, sulfate, borate, molybdate and/or selenaterepeat units) per chain based upon the non-orthophosphate fraction ofthe polyphosphate. By way of further example, in one embodiment theaverage chain length (number average) may be 2.5 to 10 repeat units(phosphate, sulfate, borate, molybdate and/or selenate repeat units) perchain based upon the non-orthophosphate fraction of the polyphosphate.By way of further example, in one embodiment the average chain length(number average) may be 3 to 15 repeat units (phosphate, sulfate,borate, molybdate and/or selenate repeat units) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe 3 to 10 repeat units (phosphate, sulfate, borate, molybdate and/orselenate repeat units) per chain based upon the non-orthophosphatefraction of the polyphosphate. By way of further example, in oneembodiment the average chain length (number average) may be 2.1 to 10repeat units (phosphate, sulfate, borate, molybdate and/or selenaterepeat units) per chain based upon the non-orthophosphate fraction ofthe polyphosphate. By way of further example, in one embodiment theaverage chain length (number average) may be 2.5 to 7 repeat units(phosphate, sulfate, borate, molybdate and/or selenate repeat units) perchain based upon the non-orthophosphate fraction of the polyphosphate.By way of further example, in one embodiment the average chain length(number average) may be 2.5 to 5 repeat units (phosphate, sulfate,borate, molybdate and/or selenate repeat units) per chain based upon thenon-orthophosphate fraction of the polyphosphate.

In some embodiments in which the calculation is based upon thenon-orthophosphate fraction of the polyphosphate, (i.e., excluding theorthophosphate fraction of the polyphosphate from the calculation), theaverage chain length (number average) may be in the range of about 2 and50 phosphate units (phosphorus atoms) per chain. For example, in oneembodiment the average chain length (number average) may be 2 to 25phosphate units (phosphorus atoms) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe 2 to 20 phosphate units (phosphorus atoms) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe 2 to 15 phosphate units (phosphorus atoms) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe 2 to 10 phosphate units (phosphorus atoms) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe 2.5 to 20 phosphate units (phosphorus atoms) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe 2.5 to 15 phosphate units (phosphorus atoms) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe 2.5 to 10 phosphate units (phosphorus atoms) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe 3 to 20 phosphate units (phosphorus atoms) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe 3 to 15 phosphate units (phosphorus atoms) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe 3 to 10 phosphate units (phosphorus atoms) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe 3.5 to 20 phosphate units (phosphorus atoms) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe 3.5 to 15 phosphate units (phosphorus atoms) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe 3.5 to 10 phosphate units (phosphorus atoms) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe 4 to 20 phosphate units (phosphorus atoms) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe 4 to 15 phosphate units (phosphorus atoms) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe 4 to 10 phosphate units (phosphorus atoms) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe 4 to 9 phosphate units (phosphorus atoms) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe 4 to 8 phosphate units (phosphorus atoms) per chain based upon thenon-orthophosphate fraction of the polyphosphate. By way of furtherexample, in one embodiment the average chain length (number average) maybe greater than 2 and less than 50 phosphate units (phosphorus atoms)per chain based upon the non-orthophosphate fraction of thepolyphosphate. By way of further example, in one embodiment the averagechain length (number average) may be 2.1 to 10 phosphate units(phosphorus atoms) per chain based upon the non-orthophosphate fractionof the polyphosphate. By way of further example, in one embodiment theaverage chain length (number average) may be 2.5 to 7 phosphate units(phosphorus atoms) per chain based upon the non-orthophosphate fractionof the polyphosphate. By way of further example, in one embodiment theaverage chain length (number average) may be 2.5 to 5 phosphate units(phosphorus atoms) per chain based upon the non-orthophosphate fractionof the polyphosphate.

On a molar basis, the polyphosphate composition also preferably containsat least 0.5 phosphate/sulfate/borate/molybdate/selenate repeat units(i.e., the combined total of phosphate, sulfate, borate, molybdate andselenate repeat units) for each atom of calcium and magnesium (incombination). In one exemplary embodiment, the polyphosphate compositioncontains at least 0.66 phosphate/sulfate/borate/molybdate/selenaterepeat units (i.e., the combined total of phosphate, sulfate, borate,molybdate and selenate repeat units) for each atom of calcium andmagnesium (in combination). By way of further example, in oneembodiment, the polyphosphate composition contains at least 0.75phosphate/sulfate/borate/molybdate/selenate repeat units for each atomof calcium and magnesium (in combination). By way of further example, inone embodiment, the polyphosphate composition contains at least 0.825phosphate/sulfate/borate/molybdate/selenate repeat units for each atomof calcium and magnesium (in combination). By way of further example, inone embodiment, the polyphosphate composition contains at least 0.95phosphate/sulfate/borate/molybdate/selenate repeat units for each atomof calcium and magnesium (in combination). By way of further example, inone embodiment, the polyphosphate composition contains no more than onealkaline earth metal atom selected from the group consisting of calcium,magnesium and a combination thereof for eachphosphate/sulfate/borate/molybdate/selenate repeat units of theinorganic polyphosphate composition. By way of further example, in oneembodiment, the polyphosphate composition contains at least 1.11phosphate/sulfate/borate/molybdate/selenate repeat units for each atomof calcium and magnesium (in combination). By way of further example, inone embodiment, the polyphosphate composition may contain about 1.33phosphate/sulfate/borate/molybdate/selenate repeat units for each atomof calcium and magnesium (in combination). By way of further example, inone embodiment, the polyphosphate composition may contain about 1.67phosphate/sulfate/borate/molybdate/selenate repeat units for each atomof calcium and magnesium (in combination). By way of further example, inone embodiment, the polyphosphate composition may contain about 2.22phosphate/sulfate/borate/molybdate/selenate repeat units for each atomof calcium and magnesium (in combination). In general, however, theupper limit of the ratio of phosphate/sulfate/borate/molybdate/selenaterepeat units to calcium and magnesium atoms is the ratio that would leadto the formation of the corresponding dihydrogen orthophosphate.

In one embodiment, on a molar basis, the polyphosphate compositionpreferably contains at least 0.5 phosphate repeat units for each atom ofcalcium and magnesium (in combination). In one exemplary embodiment, thepolyphosphate composition contains at least 0.66 phosphate units(phosphorous atom) for each atom of calcium and magnesium (incombination). By way of further example, in one embodiment, thepolyphosphate composition contains at least 0.75 phosphate units(phosphorous atom) for each atom of calcium and magnesium (incombination). By way of further example, in one embodiment, thepolyphosphate composition contains at least 0.825 phosphate units(phosphorous atom) for each atom of calcium and magnesium (incombination). By way of further example, in one embodiment, thepolyphosphate composition contains at least 0.95 phosphate units(phosphorous atom) for each atom of calcium and magnesium (incombination). By way of further example, in one embodiment, thepolyphosphate composition contains no more than one alkaline earth metalatom selected from the group consisting of calcium, magnesium and acombination thereof for each phosphate unit (phosphorous atom) of theinorganic polyphosphate composition. In one exemplary embodiment, thepolyphosphate composition contains By way of further example, in oneembodiment, the polyphosphate composition contains at least 1.11phosphate units (phosphorous atom) for each atom of calcium andmagnesium (in combination). By way of further example, in oneembodiment, the polyphosphate composition may contain about 1.33phosphate units (phosphorous atoms) for each atom of calcium andmagnesium (in combination). By way of further example, in oneembodiment, the polyphosphate composition may contain about 1.67phosphate units (phosphorous atoms) for each atom of calcium andmagnesium (in combination). By way of further example, in oneembodiment, the polyphosphate composition may contain about 2.22phosphate units (phosphorous atoms) for each atom of calcium andmagnesium (in combination). In general, however, the upper limit of theratio of phosphate units (phosphorous atoms) to calcium and magnesiumatoms is the ratio that would lead to the formation of the correspondingdihydrogen orthophosphate.

In general, it is preferred that inorganic polyphosphate compositioncontain calcium, magnesium, or a combination thereof, and that theinorganic polyphosphate have a ratio, A:Z, having a value of at least0.3:1, wherein A is the combined number of equivalents of calcium andmagnesium incorporated in the inorganic polyphosphate composition and Zis the combined number of equivalents of phosphate, sulfate, borate,molybdate, and selenate repeat units incorporated in the inorganicpolyphosphate composition. In one exemplary embodiment, A:Z is at least0.4:1. In another exemplary embodiment, A:Z is at least 0.45:1. Inanother exemplary embodiment, A:Z is at least 0.5:1. In anotherexemplary embodiment, A:Z is at least 0.52:1. In another exemplaryembodiment, A:Z is at least 0.5:1. In another exemplary embodiment, A:Zis at least 0.5:1. In another exemplary embodiment, A:Z is at least0.6:1. In another exemplary embodiment, A:Z is at least 0.5:1. Inanother exemplary embodiment, A:Z is at least 0.65:1. In anotherexemplary embodiment, A:Z is at least 0.7:1. In another exemplaryembodiment, A:Z is at least 0.5:1. In another exemplary embodiment, A:Zis at least 0.8:1. In another exemplary embodiment, A:Z is at least0.9:1. In general, however, A:Z will not exceed 1.25:1, with ratios inthe range of about 0.5:1 to about 1:1 or even about 0.5:1 to about0.75:1 being more typical. For example, in each of the foregoingembodiments, the inorganic polyphosphate composition may comprisephosphate repeat units and sulfate repeat units. By way of furtherexample, in each of the foregoing embodiments, the inorganicpolyphosphate composition may comprise phosphate repeat units andsulfate repeat units with the ratio of phosphate repeat units to sulfaterepeat units being between 10:1 and 2:1.

In some embodiments, the ratio of the number of equivalents of calciumand magnesium, in combination, for each equivalent of phosphate in thepolyphosphate composition is two-thirds of the value of thecorresponding molar ratio. Stated differently, in one embodiment theinorganic polyphosphate composition contains calcium, magnesium, or acombination thereof, and that the inorganic polyphosphate have a ratio,A:P, having a value of at least 0.3:1, wherein A is the combined numberof equivalents of calcium and magnesium incorporated in the inorganicpolyphosphate composition and P is the number of equivalents ofphosphorous, P, incorporated in the inorganic polyphosphate composition.In one exemplary embodiment, A:P is at least 0.4:1. In another exemplaryembodiment, A:P is at least 0.45:1. In another exemplary embodiment, A:Pis at least 0.5:1. In another exemplary embodiment, A:P is at least0.52:1. In another exemplary embodiment, A:P is at least 0.5:1. Inanother exemplary embodiment, A:P is at least 0.5:1. In anotherexemplary embodiment, A:P is at least 0.6:1. In another exemplaryembodiment, A:P is at least 0.5:1. In another exemplary embodiment, A:Pis at least 0.65:1. In another exemplary embodiment, A:P is at least0.7:1. In another exemplary embodiment, A:P is at least 0.5:1. Inanother exemplary embodiment, A:P is at least 0.8:1. In anotherexemplary embodiment, A:P is at least 0.9:1. In another exemplaryembodiment, A:P has a value of 0.3:1 to 1:1. In general, however, A:Pwill not exceed 1:1, with ratios in the range of about 0.5:1 to about0.75:1 being more typical.

Considered on a weight basis, in some embodiments the inorganicpolyphosphate composition comprises at least 7 weight percent of analkaline earth metal selected from calcium, magnesium and a combinationthereof, based upon the total weight of the polyphosphate. Typically,however, the polyphosphate composition will contain less than about 35weight percent of calcium and magnesium, in combination. For example,the polyphosphate composition may contain less than about 25 weightpercent of calcium and magnesium, in combination. By way of furtherexample, in one embodiment the polyphosphate composition comprises atleast 7 wt. % calcium and no, or only trace amounts of magnesium. By wayof further example, in this embodiment, the polyphosphate compositionmay contain at least 10 wt. % calcium and no, or only trace amounts ofmagnesium. By way of further example, in this embodiment, thepolyphosphate composition may contain at least 12 wt. % calcium and no,or only trace amounts of magnesium. By way of further example, in thisembodiment, the polyphosphate composition may contain at least 15 wt. %calcium and no, or only trace amounts of magnesium. By way of furtherexample, in this embodiment, the polyphosphate composition may containat least 20 wt. % calcium and no, or only trace amounts of magnesium.Alternatively, in one embodiment, the polyphosphate compositioncomprises at least 7 wt. % magnesium and no, or only trace amounts ofcalcium. By way of further example, in this embodiment, thepolyphosphate composition may contain at least 10 wt. % magnesium andno, or only trace amounts of calcium. By way of further example, in thisembodiment, the polyphosphate composition may contain at least 12 wt. %magnesium and no, or only trace amounts of calcium. By way of furtherexample, in this embodiment, the polyphosphate composition may containat least 15 wt. % magnesium and no, or only trace amounts of calcium. Byway of further example, in this embodiment, the polyphosphatecomposition may contain at least 20 wt. % magnesium and no, or onlytrace amounts of calcium. In yet another embodiment, the polyphosphatecomposition contains more than trace amounts of each of calcium andmagnesium and, in combination, calcium and magnesium constitute at least7 wt. % of the total weight of the composition. For example, in oneembodiment, the polyphosphate composition contains more than traceamounts of each of calcium and magnesium and, in combination, calciumand magnesium constitute at least 12 wt. % of the total weight of thecomposition. By way of further example, in one embodiment, thepolyphosphate composition contains more than trace amounts of each ofcalcium and magnesium and, in combination, calcium and magnesiumconstitute at least 15 wt. % of the total weight of the composition. Byway of further example, in one embodiment, the polyphosphate compositioncontains more than trace amounts of each of calcium and magnesium and,in combination, calcium and magnesium constitute at least 20 wt. % ofthe total weight of the composition.

In general, when the composition contains both calcium and magnesium, itis generally preferred that the atomic ratio of calcium to magnesium begreater than 0.2:1 (calcium:magnesium). For example, the atomic ratio ofcalcium to magnesium may be greater than 0.5:1 (calcium:magnesium). Incertain embodiments, the composition contains more calcium thanmagnesium. Thus, for example, the atomic ratio of calcium to magnesiummay exceed 1.25:1 (calcium:magnesium). In one such preferred embodiment,the atomic ratio of calcium to magnesium exceeds 1.5:1(calcium:magnesium). In one such preferred embodiment, the atomic ratioof calcium to magnesium exceeds 1.75:1 (calcium:magnesium). In one suchpreferred embodiment, the atomic ratio of calcium to magnesium exceeds2:1 (calcium:magnesium). In one such preferred embodiment, the atomicratio of calcium to magnesium exceeds 4:1 (calcium:magnesium). In onesuch preferred embodiment, the atomic ratio of calcium to magnesiumexceeds 5:1 (calcium:magnesium).

Advantageously, the polyphosphates of the present invention arewater-insoluble. That is, the phosphates do not appreciably dissolve indeionized water at room temperature (25° C.) water and neutral pH; forexample, the polyphosphates will not release more than 20% of thecombined amounts of calcium and magnesium contained by the polyphosphatecomposition within 10 minutes, and preferably within an hour.Water-insolubility may be conveniently assessed, for example, byreference to the dissolution of the polyphosphate in moderate strengthmineral acid. For example, the combined amounts of calcium and magnesium(and any micronutrient metals selected from the group consisting ofchromium, cobalt, copper, iron, manganese, selenium, and zinc) containedby the polyphosphate composition that dissolves from the inorganicpolyphosphate composition during a 30 minute period in deionized waterat room-temperature (25° C.) is less than 20% (by weight) of thecombined amount of calcium and magnesium (and any micronutrient metalsselected chromium, cobalt, copper, iron, manganese, selenium and zinc)that dissolves from the inorganic polyphosphate composition during a 30minute period in 0.1N HCl at room-temperature (25° C.). In one preferredembodiment, the amount of such metals that dissolve in DI water is lessthan 15% of the amount of such metals that dissolve in 0.1N HCl undersuch conditions. In one preferred embodiment, the amount of such metalsthat dissolve in DI water is less than 10% of the amount of such metalsthat dissolve in 0.1 N HCl under such conditions. In one preferredembodiment, the amount of such metals that dissolve in DI water is lessthan 9% of the amount of such metals that dissolve in 0.1N HCl undersuch conditions. In one preferred embodiment, the amount of such metalsthat dissolve in DI water is less than 8% of the amount of such metalsthat dissolve in 0.1N HCl under such conditions.

The polyphosphates dissolve relatively rapidly at room temperature indilute citric acid. Stated differently, the extent of dissolution in aone hour period in dilute citric acid, such as 6.9 wt. %, 2 wt. %, 1 wt.% or even 0.2 wt % or 0.1 wt. % citric acid, at room temperature is asubstantial fraction of the extent of dissolution in significantlystronger acids such as 0.1N HCl acid at room temperature. For example,the combined amount of calcium and magnesium (and any chromium, cobalt,copper, iron, manganese, selenium and zinc) that dissolves from theinorganic polyphosphate composition during a 20 minute period in 6.9 wt.% citric acid at room-temperature (25° C.) is at least 75% of thecombined amount of calcium and magnesium (and any chromium, cobalt,copper, iron, manganese, selenium and zinc) that dissolves from theinorganic polyphosphate composition during a 20 minute period in 0.1NHCl at room-temperature (25° C.); in certain more preferred embodiments,the amount that dissolves in the 2 wt. % citric acid is at 80%, 85%, 90%or even 95% of the combined amount of calcium and magnesium (and anychromium, cobalt, copper, iron, manganese, selenium and zinc) thatdissolves from the inorganic polyphosphate composition during a 20minute period in 0.1N HCl at room-temperature (25° C.). For example, thecombined amount of calcium and magnesium (and any chromium, cobalt,copper, iron, manganese, selenium and zinc) that dissolves from theinorganic polyphosphate composition during a 20 minute period in 2 wt. %citric acid at room-temperature (25° C.) is at least 75% of the combinedamount of calcium and magnesium (and any chromium, cobalt, copper, iron,manganese, selenium and zinc) that dissolves from the inorganicpolyphosphate composition during a 20 minute period in 0.1N HCl atroom-temperature (25° C.); in certain more preferred embodiments, theamount that dissolves in the 2 wt. % citric acid is at 80%, 85%, 90% oreven 95% of the combined amount of calcium and magnesium (and anychromium, cobalt, copper, iron, manganese, selenium and zinc) thatdissolves from the inorganic polyphosphate composition during a 20minute period in 0.1N HCl at room-temperature (25° C.). By way offurther example, in one embodiment the combined amount of calcium andmagnesium (and any chromium, cobalt, copper, iron, manganese, seleniumand zinc) that dissolves from the inorganic polyphosphate compositionduring a 20 minute period in 1 wt. % citric acid at room-temperature(25° C.) is at least 75% of the combined amount of calcium and magnesium(and any chromium, cobalt, copper, iron, manganese, selenium and zinc)that dissolves from the inorganic polyphosphate composition during a 20minute period in 0.1N HCl at room-temperature (25° C.); in certain morepreferred embodiments, the amount that dissolves in the 1 wt. % citricacid is at 80%, 85%, 90% or even 95% of the combined amount of calciumand magnesium (and any chromium, cobalt, copper, iron, manganese,selenium and zinc) that dissolves from the inorganic polyphosphatecomposition during a 20 minute period in 0.1N HCl at room-temperature(25° C.). By way of further example, in one embodiment the combinedamount of calcium and magnesium (and any chromium, cobalt, copper, iron,manganese, selenium and zinc) that dissolves from the inorganicpolyphosphate composition during a 20 minute period in 0.2 wt. % citricacid at room-temperature (25° C.) is at least 75% of the combined amountof calcium and magnesium (and any chromium, cobalt, copper, iron,manganese, selenium and zinc) that dissolves from the inorganicpolyphosphate composition during a 20 minute period in 0.1N HCl atroom-temperature (25° C.); in certain more preferred embodiments, theamount that dissolves in the 0.2 wt. % citric acid is at 80%, 85%, 90%or even 95% of the combined amount of calcium and magnesium (and anychromium, cobalt, copper, iron, manganese, selenium and zinc) thatdissolves from the inorganic polyphosphate composition during a 20minute period in 0.1 N HCl at room-temperature (25° C.). By way offurther example, in one embodiment the combined amount of calcium andmagnesium (and any chromium, cobalt, copper, iron, manganese, seleniumand zinc) that dissolves from the inorganic polyphosphate compositionduring a 20 minute period in 0.1 wt. % citric acid at room-temperature(25° C.) is at least 75% of the combined amount of calcium and magnesium(and any chromium, cobalt, copper, iron, manganese, selenium and zinc)that dissolves from the inorganic polyphosphate composition during a 20minute period in 0.1N HCl at room-temperature (25° C.); in certain morepreferred embodiments, the amount that dissolves in the 0.1 wt. % citricacid is at 80%, 85%, 90% or even 95% of the combined amount of calciumand magnesium (and any chromium, cobalt, copper, iron, manganese,selenium and zinc) that dissolves from the inorganic polyphosphatecomposition during a 20 minute period in 0.1N HCl at room-temperature(25° C.).

In one embodiment, the polyphosphate composition preferably alsodissolves relatively rapidly at room temperature in diluteethylenediaminetetraacetic acid (EDTA). Stated differently, the extentof dissolution in a one hour period in 0.005 M EDTA is preferably asubstantial fraction of the extent of dissolution in significantlystronger acids such as 0.1N HCl acid at room temperature. For example,the combined amount of calcium and magnesium (and any chromium, cobalt,copper, iron, manganese, selenium and zinc) that dissolves from theinorganic polyphosphate composition during a 20 minute period in 0.005MEDTA at room-temperature (25° C.) is at least 75% of the combined amountof calcium and magnesium (and any chromium, cobalt, copper, iron,manganese, selenium and zinc) that dissolves from the inorganicpolyphosphate composition during a 20 minute period in 0.1N HCl atroom-temperature (25° C.). In one preferred embodiment, the amount ofsuch metals that dissolve in 0.005M EDTA is at least 80% of the amountof such metals that dissolve in 0.1N HCl under such conditions. In onepreferred embodiment, the amount of such metals that dissolve in 0.005MEDTA is at least 85% of the amount of such metals that dissolve in 0.1 NHCl under such conditions. In one preferred embodiment, the amount ofsuch metals that dissolve in 0.005M EDTA is at least 90% of the amountof such metals that dissolve in 0.1 N HCl under such conditions. In onepreferred embodiment, the amount of such metals that dissolve in 0.005MEDTA is at least 95% of the amount of such metals that dissolve in 0.1NHCl under such conditions.

In one embodiment, the polyphosphate composition preferably alsodissolves relatively rapidly at room temperature in dilute HCl. Stateddifferently, the extent of dissolution in a one hour period in 0.01 NHCl at room temperature is a substantial fraction of the extent ofdissolution in significantly stronger acids such as 0.1N HCl acid atroom temperature. For example, the combined amount of calcium andmagnesium (and any chromium, cobalt, copper, iron, manganese, seleniumand zinc) that dissolves from the inorganic polyphosphate compositionduring a 20 minute period in 0.01N HCl at room-temperature (25° C.) isat least 75% of the combined amount of calcium and magnesium (and anychromium, cobalt, copper, iron, manganese, selenium and zinc) thatdissolves from the inorganic polyphosphate composition during a 20minute period in 0.1 N HCl at room-temperature (25° C.). In onepreferred embodiment, the amount of such metals that dissolve in 0.01 NHCl is at least 80% of the amount of such metals that dissolve in 0.1 NHCl under such conditions. In one preferred embodiment, the amount ofsuch metals that dissolve in 0.01 N HCl is at least 85% of the amount ofsuch metals that dissolve in 0.1 N HCl under such conditions. In onepreferred embodiment, the amount of such metals that dissolve in 0.01 NHCl is at least 90% of the amount of such metals that dissolve in 0.1 NHCl under such conditions. In one preferred embodiment, the amount ofsuch metals that dissolve in 0.01 N HCl is at least 95% of the amount ofsuch metals that dissolve in 0.1 N HCl under such conditions.

In one embodiment, the polyphosphate composition dissolves relativelyrapidly at room temperature in 0.2 wt. % citric acid, 0.005M EDTA and0.01N HCl. In addition, the extent of dissolution in a one hour periodin dilute acids such as 0.2 wt. % citric acid, 0.005M EDTA and 0.01N HClat room temperature is a substantial fraction of the extent ofdissolution in significantly stronger acids such as 0.1N HCl acid atroom temperature. For example, the combined amount of calcium andmagnesium (and any chromium, cobalt, copper, iron, manganese, seleniumand zinc) that dissolves from the inorganic polyphosphate compositionduring a 20 minute period in each of 0.2 wt. % citric acid, 0.005M EDTAand 0.01N HCl at room-temperature (25° C.) is at least 75% of thecombined amount of calcium and magnesium (and any chromium, cobalt,copper, iron, manganese, selenium and zinc) that dissolves from theinorganic polyphosphate composition during a 20 minute period in 0.1NHCl at room-temperature (25° C.). In one preferred embodiment, theamount of such metals that dissolve in each of the dilute acids is atleast 80% of the amount of such metals that dissolve in 0.1 N HCl undersuch conditions. In one preferred embodiment, the amount of such metalsthat dissolve in each of the dilute acids is at least 85% of the amountof such metals that dissolve in 0.1N HCl under such conditions. In onepreferred embodiment, the amount of such metals that dissolve in each ofthe dilute acids is at least 90% of the amount of such metals thatdissolve in 0.1 N HCl under such conditions. In one preferredembodiment, the amount of such metals that dissolve in each of thedilute acids is at least 95% of the amount of such metals that dissolvein 0.1 N HCl under such conditions.

In one embodiment, the polyphosphate composition dissolves relativelyrapidly at room temperature in 0.1 wt. % citric acid, 0.005M EDTA and0.01N HCl. In addition, the extent of dissolution in a one hour periodin dilute acids such as 0.1 wt. % citric acid, 0.005M EDTA and 0.01N HClat room temperature is a substantial fraction of the extent ofdissolution in significantly stronger acids such as 0.1N HCl acid atroom temperature. For example, the combined amount of calcium andmagnesium (and any chromium, cobalt, copper, iron, manganese, seleniumand zinc) that dissolves from the inorganic polyphosphate compositionduring a 20 minute period in each of 0.1 wt. % citric acid, 0.005M EDTAand 0.01N HCl at room-temperature (25° C.) is at least 75% of thecombined amount of calcium and magnesium (and any chromium, cobalt,copper, iron, manganese, selenium and zinc) that dissolves from theinorganic polyphosphate composition during a 20 minute period in 0.1NHCl at room-temperature (25° C.). In one preferred embodiment, theamount of such metals that dissolve in each of the dilute acids is atleast 80% of the amount of such metals that dissolve in 0.1N HCl undersuch conditions. In one preferred embodiment, the amount of such metalsthat dissolve in each of the dilute acids is at least 85% of the amountof such metals that dissolve in 0.1 N HCl under such conditions. In onepreferred embodiment, the amount of such metals that dissolve in each ofthe dilute acids is at least 90% of the amount of such metals thatdissolve in 0.1 N HCl under such conditions. In one preferredembodiment, the amount of such metals that dissolve in each of thedilute acids is at least 95% of the amount of such metals that dissolvein 0.1N HCl under such conditions.

Depending upon their composition, certain of the polyphosphates can becharacterized by their X-ray diffraction reflections at one or more ofthe following positions: 5.96 (±0.03), 5.37 (±0.03), 5.01 (±0.025),4.73, 4.61, 4.5, 4.15, 4.04, 3.7, 3.66(±0.01), 3.58(±0.01), 3.47(±0.01),3.39(±0.01), 3.35(±0.01), 3.19(±0.01), 3.13(±0.01), 3.09(±0.01),3.05(±0.01), 2.96(±0.009), 2.94(±0.009), 2.82(±0.009), 2.76(±0.008),2.73(±0.008), 2.59(±0.007), 2.53(±0.007), 2.5(±0.007), 2.43(±0.007),2.41(±0.007), 2.37(±0.007), 2.34(±0.006), 2.25(±0.006), 2.2(±0.006),2.18(±0.005), 2.16(±0.005), 2.14(±0.005), 2.12(±0.005), 2.09(±0.005),2.08(±0.005), 2.03(±0.005), 1.99(±0.004), 1.93(±0.004), 1.91(±0.004),1.85(±0.003), 1.8(±0.003), 1.76(±0.003), 1.72(±0.003), 1.68(±0.0028),1.64(±0.0027), 1.59(±0.0025), 1.57(±0.0024) Å.

Depending upon their composition, certain of the polyphosphates can becharacterized by their X-ray diffraction reflections at one or more ofthe following positions: 7.54(±0.03), 6.74(±0.03), 5.96 (±0.03), 5.37(±0.03), 5.01 (±0.025), 4.73, 4.61, 4.5, 4.15, 4.04, 3.7, 3.66(±0.01),3.58(±0.01), 3.47(±0.01), 3.39(±0.01), 3.35(±0.01), 3.19(±0.01),3.13(±0.01), 3.09(±0.01), 3.05(±0.01), 2.96(±0.009), 2.94(±0.009),2.82(±0.009), 2.76(±0.008), 2.73(±0.008), 2.59(±0.007), 2.53(±0.007),2.5(±0.007), 2.43(±0.007), 2.41(±0.007), 2.37(±0.007), 2.34(±0.006),2.25(±0.006), 2.2(±0.006), 2.18(±0.005), 2.16(±0.005), 2.14(±0.005),2.12(±0.005), 2.09(±0.005), 2.08(±0.005), 2.03(±0.005), 1.99(±0.004),1.93(±0.004), 1.91(±0.004), 1.85(±0.003), 1.8(±0.003), 1.76(±0.003),1.72(±0.003), 1.68(±0.0028), 1.64(±0.0027), 1.59(±0.0025), 1.57(±0.0024)Å.

Advantageously, the polyphosphate composition may comprise a range ofmetals and other ions other than calcium, magnesium, or a combinationthereof.

In an embodiment, the polyphosphate contains zinc as the onlymicronutrient. In this embodiment, the polyphosphate includes at leastabout 10 weight percent zinc, based on the total weight of thepolyphosphate. In another embodiment, the polyphosphate contains iron asthe only micronutrient. In this embodiment, the polyphosphate includesat least about 7 weight percent iron, based on the total weight of thepolyphosphate. In another embodiment, the polyphosphate containsmanganese as the only micronutrient. In this embodiment, thepolyphosphate includes at least about 5 weight percent manganese, basedon the total weight of the polyphosphate. In another embodiment, thepolyphosphate contains copper as the only micronutrient. In thisembodiment, the polyphosphate includes at least about 5 weight percentcopper, based on the total weight of the polyphosphate. In anotherembodiment, the polyphosphate contains chromium as the onlymicronutrient. In this embodiment, the polyphosphate includes at leastabout 3 weight percent chromium, based on the total weight of thepolyphosphate. In another embodiment, the polyphosphate contains cobaltas the only micronutrient. In this embodiment, the polyphosphateincludes at least 1 weight percent cobalt, based on the total weight ofthe polyphosphate. In another embodiment, the polyphosphate contains atleast two different micronutrients. In this embodiment, thepolyphosphate includes at least about 8 weight percent totalmicronutrient, based on the total weight of the polyphosphate.Alternatively, the polyphosphate preferably comprises at least about 10weight percent, alternatively at least about 15 weight percent,alternatively at least about 20 weight percent, alternatively at leastabout 22 weight percent, alternatively at least about 25 weight percent,alternatively at least about 30 weight percent, alternatively at leastabout 35 weight percent, micronutrients based on the total weight of thepolyphosphate. Alternately, the composition contains less than 30 wt. %of boron, chromium, cobalt, copper, iodine, iron, manganese, molybdenum,selenium, sulfur and zinc, in combination.

For example, the polyphosphate composition may comprise potassium as anutrient ion. Typically in this embodiment, the polyphosphatecomposition preferably contains less than about 20 wt. % potassium,based on the total weight of the polyphosphate composition. In thisembodiment, the polyphosphate composition may contain less than about 15wt. % potassium, based on the total weight of the polyphosphate; inother such embodiments, the polyphosphate contains less than 10 wt. %potassium, less than 5 wt. % potassium, or even less than 1 wt. %potassium. When included, the polyphosphate will typically compriseabout 10-15 wt. % potassium.

In one embodiment, the polyphosphate composition contains sodium (e.g.,at least about 0.01 wt. % sodium) as a nutrient ion in addition tocalcium, magnesium, or a combination thereof. In this embodiment, thepolyphosphate composition may contains less than about 10 wt. % sodium,based on the total weight of the polyphosphate; in other suchembodiments, the polyphosphate contains less than 7.5 wt. % sodium, lessthan 5 wt. % sodium, or even less than 1 wt. % sodium. When included,the polyphosphate will typically comprise about 1-5 wt. % sodium.

In one embodiment, the polyphosphate composition contains sulfur (e.g.,at least about 0.01 wt. % sulfur) as a nutrient ion in addition tocalcium, magnesium, or a combination thereof. In this embodiment, thepolyphosphate composition preferably may contain less than about 10 wt.% sulfur, based on the total weight of the polyphosphate; in other suchembodiments, the polyphosphate contains less than 7 wt. % sulfur, lessthan 5 wt. % sulfur, or even less than 1 wt. % sulfur. When included,the polyphosphate will typically comprise about 1 to 7 wt. % sulfur.

In one embodiment, the polyphosphate composition contains ammonium(e.g., at least about 0.01 wt. % ammonium) as a nutrient ion in additionto calcium, magnesium, or a combination thereof. In this embodiment, thepolyphosphate composition may contain less than about 10 wt. % ammonium,based on the total weight of the polyphosphate; in other suchembodiments, the polyphosphate contains less than 7.5 wt. % ammonium,less than 5 wt. % ammonium, or even less than 1 wt. % ammonium. Whenincluded, the polyphosphate will typically comprise about 1-10 wt. %ammonium. When included, the polyphosphate will typically comprise about1-5 wt. % ammonium.

In one embodiment, the polyphosphate composition contains zinc (e.g., atleast about 0.01 wt. % zinc) as a nutrient ion in addition to calcium,magnesium, or a combination thereof. In this embodiment, thepolyphosphate composition may contain less than about 9 weight percentzinc, based on the total weight of the polyphosphate; in other suchembodiments, the polyphosphate contains less than 6 wt. % zinc, lessthan 5 wt. % zinc, less than 4 wt. % zinc, less than 3 wt. % zinc, lessthan 2 wt. % zinc, less than 1 wt. % zinc, less than 0.5 wt. % zinc,less than 0.25 wt. % zinc, or even less than 0.1 wt. % zinc. Whenincluded, the polyphosphate will typically comprise about 1-35 wt. %zinc.

In one embodiment, the polyphosphate composition contains iron (e.g., atleast about 0.01 wt. % iron) as a nutrient ion in addition to calcium,magnesium, or a combination thereof. In this embodiment, thepolyphosphate composition may contain less than about 6 weight percentiron, based on the total weight of the polyphosphate; in other suchembodiments, the polyphosphate contains less than 5 wt. % iron, lessthan 4 wt. % iron, less than 3 wt. % iron, less than 2 wt. % iron, lessthan 1 wt. % iron, less than 0.5 wt. % iron, less than 0.25 wt. % iron,or even less than 0.1 wt. % iron. When included, the polyphosphate willtypically comprise about 1-10 wt. % iron.

In one embodiment, the polyphosphate composition contains manganese(e.g., at least about 0.01 wt % manganese) as a nutrient ion in additionto calcium, magnesium, or a combination thereof. In this embodiment, thepolyphosphate composition may contain less than about 5 weight percentmanganese, based on the total weight of the polyphosphate; 4 weightpercent manganese, based on the total weight of the polyphosphate; inother such embodiments, the polyphosphate contains less than 4 wt. %manganese, less than 3 wt. % manganese, less than 2 wt. % manganese,less than 1 wt. % manganese, less than 0.5 wt. % manganese, less than0.25 wt. % manganese, or even less than 0.1 wt. % manganese. Whenincluded, the polyphosphate will typically comprise about 1-10 wt. %manganese.

In one embodiment, the polyphosphate composition contains copper (e.g.,at least about 0.01 wt. % copper) as a nutrient ion in addition tocalcium, magnesium, or a combination thereof. In this embodiment, thepolyphosphate composition may contain less than about 12 weight percentcopper, 4 weight percent copper, based on the total weight of thepolyphosphate; in other such embodiments, the polyphosphate containsless than 5 wt. % copper, less than 4 wt. % copper, less than 3 wt. %copper, less than 2 wt. % copper, less than 1 wt. % copper, less than0.5 wt. % copper, less than 0.25 wt. % copper, or even less than 0.1 wt.% copper. When included, the polyphosphate will typically comprise about1-35 wt. % copper.

In one embodiment, the polyphosphate composition contains chromium(e.g., at least about 0.01 wt. % chromium) as a nutrient ion in additionto calcium, magnesium, or a combination thereof. In this embodiment, thepolyphosphate composition may contain less than about 5 weight percentchromium, based on the total weight of the polyphosphate; in other suchembodiments, the polyphosphate contains less than 4 wt. % chromium, lessthan 3 wt. % chromium, less than 2 wt. % chromium, less than 1 wt. %chromium, less than 0.5 wt. % chromium, less than 0.25 wt. % chromium,or even less than 0.1 wt. % chromium.

In one embodiment, the polyphosphate composition contains cobalt (e.g.,at least about 0.01 wt. % cobalt) as a nutrient ion in addition tocalcium, magnesium, or a combination thereof. In this embodiment, thepolyphosphate composition may contain less than about 15 weight percentcobalt, based on the total weight of the polyphosphate; in other suchembodiments, the polyphosphate contains less than 4 wt. % cobalt, lessthan 3 wt. % cobalt, less than 2 wt. % cobalt, less than 1 wt. % cobalt,less than 0.9 wt. % cobalt, less than 0.75 wt. % cobalt, less than 0.5wt. % cobalt, less than 0.25 wt. % cobalt, less than 0.1 wt. % cobalt,or even less than 0.05 wt. % cobalt.

In one embodiment, the polyphosphate composition contains selenium(e.g., at least about 0.01 wt. % selenium) as a nutrient ion in additionto calcium, magnesium, or a combination thereof. In this embodiment, thepolyphosphate composition may contain less than about 10 weight percentselenium, based on the total weight of the polyphosphate; in other suchembodiments, the polyphosphate contains less than 5 wt. % selenium, lessthan 3 wt. % selenium, less than 1 wt. % selenium, less than 0.5 wt. %selenium, less than 0.5 wt. % selenium, less than 0.9 wt. % selenium,less than 0.75 wt. % selenium, less than 0.5 wt. % selenium, less than0.25 wt. % selenium, less than 0.1 wt. % selenium, or even less than0.05 wt. % selenium.

In one embodiment, the polyphosphate composition contains boron (e.g.,at least about 0.01 wt. % boron) as a nutrient ion in addition tocalcium, magnesium, or a combination thereof. In this embodiment, thepolyphosphate composition may contain less than about 10 weight percentboron, based on the total weight of the polyphosphate; in other suchembodiments, the polyphosphate contains less than 5 wt. % boron, lessthan 2 wt. % boron, less than 1.75 wt. % boron, less than 1.5 wt. %boron, less than 1.25 wt. % boron, less than 1 wt. % boron, less than0.75 wt. % boron, less than 0.5 wt. % boron, less than 0.25 wt. % boron,less than 0.1 wt. % boron, less than 0.075 wt. % boron, less than 0.05wt. % boron, less than 0.025 wt. % boron, or even about 0.01 wt. %boron.

In one embodiment, the polyphosphate composition contains iodine (e.g.,at least about 0.01 wt. % iodine) as a nutrient ion in addition tocalcium, magnesium, or a combination thereof.

In one embodiment, the polyphosphate composition contains molybdenum(e.g., at least about 0.01 wt. % molybdenum) as a nutrient ion inaddition to calcium, magnesium, or a combination thereof. In thisembodiment, the polyphosphate composition may contain less than about 10weight percent molybdenum, based on the total weight of thepolyphosphate; in other such embodiments, the polyphosphate containsless than 5 wt. % molybdenum, less than 3 wt. % molybdenum, less than 2wt. % molybdenum, less than 1 wt. % molybdenum, less than 0.09 wt. %molybdenum, less than 0.075 wt. % molybdenum, less than 0.05 wt. %molybdenum, less than 0.025 wt. % molybdenum, or even about 0.01 wt. %molybdenum.

In one embodiment, the polyphosphate composition contains at least 0.01wt. % of each of at least two different nutrients selected from thegroup consisting of boron, chromium, cobalt, copper, iodine, iron,manganese, molybdenum, selenium, sulfur and zinc. For example in onesuch embodiment, the polyphosphate composition contains up to about 15weight percent of such nutrients, combined, based on the total weight ofthe polyphosphate composition. For example, in one such embodiment, thepolyphosphate composition contains less than about 10 weight percent ofsuch nutrients, combined, based on the total weight of the polyphosphatecomposition. By way of further example, in one such embodiment, thepolyphosphate composition contains less than about 7 weight percent ofsuch nutrients, combined, based on the total weight of the polyphosphatecomposition. By way of further example, in one such embodiment, thepolyphosphate composition contains less than about 6 weight percent ofsuch nutrients, combined, based on the total weight of the polyphosphatecomposition. By way of further example, in one such embodiment, thepolyphosphate composition contains less than about 5 weight percent ofsuch nutrients, combined, based on the total weight of the polyphosphatecomposition. By way of further example, in one such embodiment, thepolyphosphate composition contains less than about 4.5 weight percent ofsuch nutrients, combined, based on the total weight of the polyphosphatecomposition. By way of further example, in one such embodiment, thepolyphosphate composition contains less than about 4 weight percent ofsuch nutrients, combined, based on the total weight of the polyphosphatecomposition. By way of further example, in one such embodiment, thepolyphosphate composition contains less than about 3.5 weight percent ofsuch nutrients, combined, based on the total weight of the polyphosphatecomposition. By way of further example, in one such embodiment, thepolyphosphate composition contains less than about 3 weight percent ofsuch nutrients, combined, based on the total weight of the polyphosphatecomposition. By way of further example, in one such embodiment, thepolyphosphate composition contains less than about 2.5 weight percent ofsuch nutrients, combined, based on the total weight of the polyphosphatecomposition. By way of further example, in one such embodiment, thepolyphosphate composition contains less than about 2 weight percent ofsuch nutrients, combined, based on the total weight of the polyphosphatecomposition. By way of further example, in one such embodiment, thepolyphosphate composition contains less than about 1.5 weight percent ofsuch nutrients, combined, based on the total weight of the polyphosphatecomposition. By way of further example, in one such embodiment, thepolyphosphate composition contains less than about 1 weight percent ofsuch nutrients, combined, based on the total weight of the polyphosphatecomposition. By way of further example, in one such embodiment, thepolyphosphate composition contains less than about 0.5 weight percent ofsuch nutrients, combined, based on the total weight of the polyphosphatecomposition.

For use as a fertilizer, the polyphosphate compositions of the presentinvention may optionally contain, in addition to one or more ofammonium, boron, chromium, cobalt, copper, iodine, iron, manganese,molybdenum, potassium, selenium, sodium, sulfur and zinc, othercomponents that contribute to the nutritional, material handling, orother characteristics of the fertilizer. For example, the fertilizercomposition may contain a water-soluble N—P—K macronutrient fertilizercomposition that has been blended or otherwise combined with thealkaline earth metal polyphosphate composition. By way of furtherexample, the fertilizer may contain organic materials like plantresidues that have been blended or otherwise combined with themicronutrient metal polyphosphate composition to improve the materialhandling characteristics of the fertilizer.

In general, the alkaline earth metal polyphosphate is preferably asolid, free-flowing particulate material. Particle size is not narrowlycritical but is generally preferably less than 80 mesh BS. Stateddifferently, a mass of the particulate polyphosphate composition has asize distribution with substantially all of the particles having a sizeless than 80 mesh BS. In one embodiment, a significant fraction of theparticles have a size less than 150 mesh BS. For example, in oneembodiment the majority of the particles in a population of particlesare less than 150 mesh BS. By way of further example, in one embodimenta significant fraction of the particles may be smaller than 300 mesh BS;in one such embodiment, the particles have a size distribution withabout 20% by volume of the particles having a size less than 300 meshBS.

In general, the polyphosphate composition is preferably a solid,free-flowing particulate material with relatively low moisture content.Typically, the polyphosphate composition comprises less than 20 wt. %moisture. For example, in certain embodiments, the polyphosphatecomposition comprises less than 10 wt. % moisture. For example, incertain embodiments, the polyphosphate composition comprises less than 8wt. % moisture. By way of further example, in certain embodiments thepolyphosphate composition comprises less than 5 wt. % moisture.

Alkaline Earth Metal Polyphosphates

In another embodiment, the polyphosphate composition comprises calciumas the only cation (other than protons). In such embodiments, the ratioof the combined number of moles of phosphorus, sulfur, boron,molybdenum, selenium (incorporated in the phosphate, sulfate, borate,molybdate and selenate repeat units) to moles of calcium in the calciumpolyphosphate may be greater than 0.5:1, respectively. By way of furtherexample, the ratio of the moles of phosphorus, sulfur, boron,molybdenum, selenium (incorporated in the phosphate, sulfate, borate,molybdate and selenate repeat units) to moles of calcium in the calciumpolyphosphate may be greater than 0.66:1, respectively. By way offurther example, the ratio of the moles of phosphorus, sulfur, boron,molybdenum, selenium (incorporated in the phosphate, sulfate, borate,molybdate and selenate repeat units) to moles of calcium in the calciumpolyphosphate may be greater than 1.1:1, respectively. By way of furtherexample, the ratio of the moles of phosphorus, sulfur, boron,molybdenum, selenium (incorporated in the phosphate, sulfate, borate,molybdate and selenate repeat units) to moles of calcium in the calciumpolyphosphate may be greater than 1.67:1, respectively.

In certain embodiments, the ratio of the moles of phosphorus to moles ofcalcium in the calcium polyphosphate may be greater than 0.5:1,respectively. By way of further example, the ratio of the moles ofphosphorus to moles of calcium in the calcium polyphosphate may begreater than 0.66:1, respectively. By way of further example, the ratioof the moles of phosphorus to moles of calcium in the calciumpolyphosphate may be greater than 1.1:1, respectively. By way of furtherexample, the ratio of the moles of phosphorus to moles of calcium in thecalcium polyphosphate may be greater than 1.67:1, respectively.

In another embodiment, the polyphosphate composition comprises magnesiumas the only cation (other than protons). In such embodiments, the ratioof the combined number of moles of phosphorus, sulfur, boron,molybdenum, selenium (incorporated in the phosphate, sulfate, borate,molybdate and selenate repeat units) to moles of magnesium in themagnesium polyphosphate may be greater than 0.5:1, respectively. By wayof further example, the ratio of the moles of phosphorus, sulfur, boron,molybdenum, selenium (incorporated in the phosphate, sulfate, borate,molybdate and selenate repeat units) to moles of magnesium in themagnesium polyphosphate may be greater than 0.66:1, respectively. By wayof further example, the ratio of the moles of phosphorus, sulfur, boron,molybdenum, selenium (incorporated in the phosphate, sulfate, borate,molybdate and selenate repeat units) to moles of magnesium in themagnesium polyphosphate may be greater than 1.1:1, respectively. By wayof further example, the ratio of the moles of phosphorus, sulfur, boron,molybdenum, selenium (incorporated in the phosphate, sulfate, borate,molybdate and selenate repeat units) to moles of magnesium in themagnesium polyphosphate may be greater than 1.67:1, respectively.

In some embodiments, the ratio of the moles of phosphorus to moles ofmagnesium in the magnesium polyphosphate may be greater than 0.5:1,respectively. By way of further example, the ratio of the moles ofphosphorus to moles of magnesium in the magnesium polyphosphate may begreater than 0.66:1, respectively. By way of further example, the ratioof the moles of phosphorus to moles of magnesium in the magnesiumpolyphosphate may be greater than 1.1:1, respectively. By way of furtherexample, the ratio of the moles of phosphorus to moles of magnesium inthe magnesium polyphosphate may be greater than 1.67:1, respectively.

In another embodiment, the polyphosphate composition comprises calciumand magnesium as the only cations (other than protons). For example, theratio of moles of calcium to moles of magnesium may be greater than0.2:1, respectively. By way of further example, the ratio of the molesof calcium to moles of magnesium may be greater than 0.5:1,respectively. By way of further example, the ratio of the moles ofcalcium to moles of magnesium may be greater than 1:1, respectively. Byway of further example, the ratio of the moles of calcium to moles ofmagnesium may be greater than 2:1, respectively. By way of furtherexample, the ratio of moles of calcium to moles of magnesium may begreater than 4:1, respectively. By way of further example, the ratio ofthe moles of calcium to moles of magnesium may be greater than 5:1,respectively. By way of further example, the ratio of the combinednumber of moles of phosphorus, sulfur, boron, molybdenum, and selenium(incorporated in the phosphate, sulfate, borate, molybdate and selenaterepeat units) to moles of calcium and magnesium (in combination) in thepolyphosphate may be greater than 0.67:1, respectively. By way offurther example, the ratio of the combined number of moles ofphosphorus, sulfur, boron, molybdenum, and selenium (incorporated in thephosphate, sulfate, borate, molybdate and selenate repeat units) tomoles of calcium and magnesium (in combination) in the polyphosphate maybe greater than 0.74:1, respectively. By way of further example, theratio of the combined number of moles of phosphorus, sulfur, boron,molybdenum, and selenium (incorporated in the phosphate, sulfate,borate, molybdate and selenate repeat units) to moles of calcium andmagnesium (in combination) in the polyphosphate may be greater than0.83:1, respectively. By way of further example, the ratio of thecombined number of moles of phosphorus, sulfur, boron, molybdenum, andselenium (incorporated in the phosphate, sulfate, borate, molybdate andselenate repeat units) to moles of calcium and magnesium (incombination) in the polyphosphate may be greater than 0.95:1,respectively. By way of further example, the ratio of the combinednumber of moles of phosphorus, sulfur, boron, molybdenum, and selenium(incorporated in the phosphate, sulfate, borate, molybdate and selenaterepeat units) to moles of calcium and magnesium (in combination) in thepolyphosphate may be greater than 1.1:1, respectively. By way of furtherexample, the ratio of the combined number of moles of phosphorus,sulfur, boron, molybdenum, and selenium (incorporated in the phosphate,sulfate, borate, molybdate and selenate repeat units) to moles ofcalcium and magnesium (in combination) in the polyphosphate may begreater than 1.33:1, respectively. By way of further example, the ratioof the combined number of moles of phosphorus, sulfur, boron,molybdenum, and selenium (incorporated in the phosphate, sulfate,borate, molybdate and selenate repeat units) to moles of calcium andmagnesium (in combination) in the polyphosphate may be equal to 1.67.1,respectively.

In certain embodiments, the ratio of the moles of phosphorus to moles ofcalcium and magnesium (in combination) in the polyphosphate may begreater than 0.5:1, respectively. By way of further example, the ratioof the moles of phosphorus to moles of calcium and magnesium (incombination) in the polyphosphate may be greater than 0.67:1,respectively. By way of further example, the ratio of the moles ofphosphorus to moles of calcium and magnesium (in combination) in thepolyphosphate may be greater than 0.74:1, respectively. By way offurther example, the ratio of the moles of phosphorus to moles ofcalcium and magnesium (in combination) in the polyphosphate may begreater than 0.83:1, respectively. By way of further example, the ratioof the moles of phosphorus to moles of calcium and magnesium (incombination) in the polyphosphate may be greater than 0.95:1,respectively. By way of further example, the ratio of the moles ofphosphorus to moles of calcium and magnesium (in combination) in thepolyphosphate may be greater than 1.1:1, respectively. By way of furtherexample, the ratio of the moles of phosphorus to moles of calcium andmagnesium (in combination) in the polyphosphate may be greater than1.33:1, respectively. By way of further example, the ratio of the molesof phosphorus to moles of calcium and magnesium (in combination) in thepolyphosphate may be equal to 1.67.1, respectively.

In one embodiment, the polyphosphate composition comprises calcium,magnesium and one nutrient ion as the only cations (other than protons).For example, alkaline earth metal polyphosphate composition may compriseonly calcium and magnesium and zinc as the only cations (other thanprotons). By way of further example, the ratio of the combined number ofmoles of phosphorus, sulfur, boron, molybdenum and selenium incorporatedin the repeat units to moles of zinc in the polyphosphate may be atleast 2:1, respectively. By way of further example, the ratio of thecombined number of moles of phosphorus, sulfur, boron, molybdenum andselenium incorporated in the repeat units to moles of zinc in thepolyphosphate may be greater than 5:1, respectively. By way of furtherexample, the ratio of the moles of phosphorus to moles of zinc in thepolyphosphate may be greater than 5:1, respectively. By way of furtherexample, the ratio of the combined number of moles of phosphorus,sulfur, boron, molybdenum and selenium incorporated in the repeat unitsto moles of zinc in the polyphosphate may be greater than 10:1,respectively. By way of further example, the ratio of the moles ofphosphorus to moles of zinc in the polyphosphate may be greater than10:1, respectively. By way of further example, the ratio of the combinednumber of moles of phosphorus, sulfur, boron, molybdenum and seleniumincorporated in the repeat units to moles of zinc in the polyphosphatemay be greater than 20:1, respectively. By way of further example, theratio of the moles of phosphorus to moles of zinc in the polyphosphatemay be greater than 20:1, respectively.

In one embodiment, the polyphosphate composition comprises calcium,magnesium and one nutrient ion as the only cations (other than protons).For example, alkaline earth metal polyphosphate composition may compriseonly calcium and magnesium and zinc as the only cations (other thanprotons). The ratio of the equivalents of zinc to phosphorous in thealkaline earth metal polyphosphate when the polyphosphate compositioncomprises calcium, magnesium and one nutrient ion as the only cations(other than protons). In one embodiment, the alkaline earth metalpolyphosphate composition comprises zinc as the only primarymicronutrient metal. In such embodiments, the ratio of the equivalentsof zinc to phosphorous in the polyphosphate may be 0.33:1, respectively.By way of further example, in one embodiment in which zinc is the onlyprimary micronutrient metal, the ratio of the equivalents of zinc tophosphorous in the alkaline earth metal polyphosphate may be less than0.33:1, respectively. By way of further example, in one embodiment inwhich zinc is the only primary micronutrient metal, the ratio of theequivalents of zinc to phosphorous in the alkaline earth metalpolyphosphate may be less than 0.3:1, respectively. By way of furtherexample, in one embodiment in which zinc is the only primarymicronutrient metal, the ratio of the equivalents of zinc to phosphorousin the alkaline earth metal polyphosphate may be less than 0.2:1,respectively. By way of further example, in one embodiment in which zincis the only primary micronutrient metal, the ratio of the equivalents ofzinc to phosphorous in the alkaline earth metal polyphosphate may beless than 0.1:1, respectively.

In one embodiment, the polyphosphate composition comprises calcium,magnesium and one nutrient ion as the only cations (other than protons).For example, the polyphosphate composition may comprise only calcium,magnesium and iron as the only cations (other than protons). By way offurther example, the ratio of the combined number of moles ofphosphorus, sulfur, boron, molybdenum and selenium incorporated in therepeat units to moles of iron in the polyphosphate may be greater than3:1. By way of further example, the ratio of the combined number ofmoles of phosphorus, sulfur, boron, molybdenum and selenium incorporatedin the repeat units to moles of iron in the polyphosphate may be greaterthan 5:1, respectively. By way of further example, the ratio of themoles of phosphorus to moles of iron in the polyphosphate may be greaterthan 5:1, respectively. By way of further example, the ratio of thecombined number of moles of phosphorus, sulfur, boron, molybdenum andselenium incorporated in the repeat units to moles of iron in thepolyphosphate may be greater than 10:1, respectively. By way of furtherexample, the ratio of the moles of phosphorus to moles of iron in thepolyphosphate may be greater than 10:1, respectively. By way of furtherexample, the ratio of the combined number of moles of phosphorus,sulfur, boron, molybdenum and selenium incorporated in the repeat unitsto moles of iron in the polyphosphate may be greater than 20:1,respectively. By way of further example, the ratio of the moles ofphosphorus to moles of iron in the polyphosphate may be greater than20:1, respectively.

In one embodiment, the polyphosphate composition comprises calcium,magnesium and one nutrient ion as the only cations (other than protons).For example, alkaline earth metal polyphosphate composition may compriseonly calcium and magnesium and iron as the only cations (other thanprotons). In one embodiment, the alkaline earth metal polyphosphatecomposition comprises iron as the only primary micronutrient metal. Insuch embodiments, the ratio of the equivalents of iron to phosphorous inthe polyphosphate may be 0.33:1, respectively. By way of furtherexample, in one embodiment in which iron is the only primarymicronutrient metal, the ratio of the equivalents of iron to phosphorousin the alkaline earth metal polyphosphate may be less than 0.33:1,respectively. By way of further example, in one embodiment in which ironis the only primary micronutrient metal, the ratio of the equivalents ofiron to phosphorous in the alkaline earth metal polyphosphate may beless than 0.3:1, respectively. By way of further example, in oneembodiment in which iron is the only primary micronutrient metal, theratio of the equivalents of iron to phosphorous in the alkaline earthmetal polyphosphate may be less than 0.2:1, respectively. By way offurther example, in one embodiment in which iron is the only primarymicronutrient metal, the ratio of the equivalents of zinc to phosphorousin the alkaline earth metal polyphosphate may be less than 0.1:1,respectively.

In one embodiment, the polyphosphate composition comprises calcium,magnesium and one nutrient ion as the only cations (other than protons).For example, polyphosphate composition may comprise only calcium andmagnesium and manganese as the only cations (other than protons). By wayof further example, the ratio of the combined number of moles ofphosphorus, sulfur, boron, molybdenum and selenium incorporated in therepeat units to moles of manganese in the polyphosphate may be greaterthan 2:1, respectively. By way of further example, the ratio of thecombined number of moles of phosphorus, sulfur, boron, molybdenum andselenium incorporated in the repeat units to moles of manganese in thepolyphosphate may be greater than 4:1, respectively. By way of furtherexample, the ratio of the combined number of moles of phosphorus,sulfur, boron, molybdenum and selenium incorporated in the repeat unitsto moles of manganese in the polyphosphate may be greater than 3:1,respectively. By way of further example, the ratio of the combinednumber of moles of phosphorus, sulfur, boron, molybdenum and seleniumincorporated in the repeat units to moles of manganese in thepolyphosphate may be greater than 5:1, respectively. By way of furtherexample, the ratio of the moles of phosphorus to moles of manganese toin the polyphosphate may be greater than 5:1, respectively. By way offurther example, the ratio of the combined number of moles ofphosphorus, sulfur, boron, molybdenum and selenium incorporated in therepeat units to moles of manganese in the polyphosphate may be greaterthan 10:1, respectively. By way of further example, the ratio of themoles of phosphorus to moles of manganese to in the polyphosphate may begreater than 10:1, respectively. By way of further example, the ratio ofthe combined number of moles of phosphorus, sulfur, boron, molybdenumand selenium incorporated in the repeat units to moles of manganese inthe polyphosphate may be greater than 20:1, respectively. By way offurther example, the ratio of the moles of phosphorus to moles ofmanganese in the polyphosphate may be greater than 20:1, respectively.

In one embodiment, the polyphosphate composition comprises calcium,magnesium and one nutrient ion as the only cations (other than protons).For example, alkaline earth metal polyphosphate composition may compriseonly calcium and magnesium and manganese as the only cations (other thanprotons). In one embodiment, the alkaline earth metal polyphosphatecomposition comprises manganese as the only primary micronutrient metal.In such embodiments, the ratio of the equivalents of manganese tophosphorous in the polyphosphate may be 0.33:1, respectively. By way offurther example, in-one embodiment in which manganese is the onlyprimary micronutrient metal, the ratio of the equivalents of manganeseto phosphorous in the alkaline earth metal polyphosphate may be lessthan 0.33:1, respectively. By way of further example, in one embodimentin which manganese is the only primary micronutrient metal, the ratio ofthe equivalents of manganese to phosphorous in the alkaline earth metalpolyphosphate may be less than 0.3:1, respectively. By way of furtherexample, in one embodiment in which manganese is the only primarymicronutrient metal, the ratio of the equivalents of manganese tophosphorous in the alkaline earth metal polyphosphate may be less than0.2:1, respectively. By way of further example, in one embodiment inwhich manganese is the only primary micronutrient metal, the ratio ofthe equivalents of zinc to phosphorous in the alkaline earth metalpolyphosphate may be less than 0.1:1, respectively.

In one embodiment, the alkaline earth metal polyphosphate compositioncomprises calcium, magnesium and one nutrient ion as the only cations(other than protons). For example, alkaline earth metal polyphosphatecomposition may comprise calcium, magnesium and boron as the onlycations (other than protons). By way of further example, the ratio ofthe moles of phosphorus to moles of boron to in the polyphosphate may begreater than 2:1, respectively. By way of further example, the ratio ofthe moles of phosphorus to moles of boron to in the polyphosphate may begreater than 5:1, respectively. By way of further example, the ratio ofthe moles of phosphorus to moles of boron to in the polyphosphate may begreater than 10:1, respectively. By way of further example, the ratio ofthe moles of phosphorus to moles of boron in the polyphosphate may begreater than 20:1, respectively.

In one embodiment, the alkaline earth metal polyphosphate compositioncomprises calcium, magnesium and one nutrient ion as the only cations(other than protons). For example, alkaline earth metal polyphosphatecomposition may comprise calcium, magnesium and copper as the onlycations (other than protons). By way of further example, the ratio ofthe combined number of moles of phosphorus, sulfur, boron, molybdenumand selenium incorporated in the repeat units to moles of copper in thepolyphosphate may be greater than 2:1, respectively. By way of furtherexample, the ratio of the moles of phosphorus to moles of copper in thepolyphosphate may be greater than 3:1, respectively. By way of furtherexample, the ratio of the combined number of moles of phosphorus,sulfur, boron, molybdenum and selenium incorporated in the repeat unitsto moles of copper in the polyphosphate may be greater than 5:1,respectively. By way of further example, the ratio of the moles ofphosphorus to moles of copper in the polyphosphate may be greater than5:1, respectively. By way of further example, the ratio of the combinednumber of moles of phosphorus, sulfur, boron, molybdenum and seleniumincorporated in the repeat units to moles of copper in the polyphosphatemay be greater than 10:1, respectively. By way of further example, theratio of the moles of phosphorus to moles of copper in the polyphosphatemay be greater than 10:1, respectively. By way of further example, theratio of the combined number of moles of phosphorus, sulfur, boron,molybdenum and selenium incorporated in the repeat units to moles ofcopper in the polyphosphate may be greater than 20:1, respectively. Byway of further example, the ratio of the moles of phosphorus to moles ofcopper in the polyphosphate may be greater than 20:1, respectively.

In one embodiment, the polyphosphate composition comprises calcium,magnesium and one nutrient ion as the only cations (other than protons).For example, alkaline earth metal polyphosphate composition may compriseonly calcium and magnesium and copper as the only cations (other thanprotons). In one embodiment, the alkaline earth metal polyphosphatecomposition comprises copper as the only primary micronutrient metal. Insuch embodiments, the ratio of the equivalents of copper to phosphorousin the polyphosphate may be 0.33:1, respectively. By way of furtherexample, in one embodiment in which copper is the only primarymicronutrient metal, the ratio of the equivalents of copper tophosphorous in the alkaline earth metal polyphosphate may be less than0.33:1, respectively. By way of further example, in one embodiment inwhich copper is the only primary micronutrient metal, the ratio of theequivalents of copper to phosphorous in the alkaline earth metalpolyphosphate may be less than 0.3:1, respectively. By way of furtherexample, in one embodiment in which copper is the only primarymicronutrient metal, the ratio of the equivalents of copper tophosphorous in the alkaline earth metal polyphosphate may be less than0.2:1, respectively. By way of further example, in one embodiment inwhich copper is the only primary micronutrient metal, the ratio of theequivalents of zinc to phosphorous in the alkaline earth metalpolyphosphate may be less than 0.1:1, respectively.

In one embodiment, the alkaline earth metal polyphosphate compositioncomprises calcium, magnesium, and one nutrient ion as the only cations(other than protons). For example, alkaline earth metal polyphosphatecomposition may comprise calcium, magnesium and selenium as the onlycations (other than protons). By way of further example, the ratio ofthe moles of phosphorus to moles of selenium in the polyphosphate may begreater than 2:1, respectively. By way of further example, the ratio ofthe moles of phosphorus to moles of selenium in the polyphosphate may begreater than 5:1, respectively. By way of further example, the ratio ofthe moles of phosphorus to moles of selenium in the polyphosphate may begreater than 10:1, respectively. By way of further example, the ratio ofthe moles of phosphorus to moles of selenium in the polyphosphate may begreater than 20:1, respectively.

In one embodiment, the alkaline earth metal polyphosphate compositioncomprises calcium, magnesium, and one nutrient ion as the only cations(other than protons). For example, alkaline earth metal polyphosphatecomposition may comprise calcium, magnesium and molybdenum as the onlycations (other than protons). By way of further example, the ratio ofthe moles of phosphorus to moles of molybdenum in the polyphosphate maybe greater than 2:1, respectively. By way of further example, the ratioof the moles of phosphorus to moles of molybdenum in the polyphosphatemay be greater than 5:1, respectively. By way of further example, theratio of the moles of phosphorus to moles of molybdenum in thepolyphosphate may be greater than 10:1, respectively. By way of furtherexample, the ratio of the moles of phosphorus to moles of molybdenum inthe polyphosphate may be greater than 20:1, respectively.

More generally, in certain embodiments the ratio of the moles ofphosphorus to moles of nutrient ions (selected from among boron,chromium, cobalt, copper, iodine, iron, manganese, molybdenum, selenium,sulfur and zinc) will be greater than 2:1, respectively. For example, inone embodiment in which the polyphosphate comprises two or more nutrientions (selected from among boron, chromium, cobalt, copper, iodine, iron,manganese, molybdenum, selenium and zinc), the ratio of the moles ofphosphorus to moles of the nutrient ions will be greater than 5:1,respectively. For example, in one embodiment in which the polyphosphatecomprises two or more nutrient ions (selected from among boron,chromium, cobalt, copper, iodine, iron, manganese, molybdenum, seleniumand zinc), the ratio of the moles of phosphorus to moles of the nutrientions will be greater than 10:1, respectively. For example, in oneembodiment in which the polyphosphate comprises two or more nutrientions (selected from among boron, chromium, cobalt, copper, iodine, iron,manganese, molybdenum, selenium, sulfur and zinc), the ratio of themoles of phosphorus to moles of the nutrient ions will be greater than20:1, respectively.

As described elsewhere herein, the polyphosphate compositions may beneutralized post-polymerization for improved material handlingcharacteristics. In general, it is preferred that the equilibrium pH ofan aqueous mixture of ten parts by weight of water at neutral pH and onepart by weight of the neutralized polyphosphate be at least pH 2. Morepreferably, the equilibrium pH of an aqueous mixture of ten parts byweight of water at neutral pH and one part by weight of the neutralizedpolyphosphate be at least pH 3. Still more preferably, the equilibriumpH of an aqueous mixture of ten parts by weight of water at neutral pHand one part by weight of the neutralized polyphosphate be at least pH4. Still more preferably, the equilibrium pH of an aqueous mixture often parts by weight of water at neutral pH and one part by weight of theneutralized polyphosphate be at least pH 5. In certain embodiments, theequilibrium pH of an aqueous mixture of ten parts by weight of water atneutral pH and one part by weight of the neutralized polyphosphate be atleast pH 6. For example, in one embodiment, the equilibrium pH of anaqueous mixture of ten parts by weight of water at neutral pH and onepart by weight of the neutralized polyphosphate will be in the range ofpH 4-8.

Calcium Polyphosphate Compositions

In one embodiment, the polyphosphate composition of the presentinvention comprises calcium as a cation. In general, polyphosphatecompositions containing calcium as a cation contain at least 7 wt. %calcium. Typically, polyphosphate compositions containing calcium as acation contain at least 10 wt. % calcium. In certain embodiments,polyphosphate compositions containing calcium as a cation contain atleast 13 wt. % calcium. In certain embodiments, polyphosphatecompositions containing calcium as a cation contain at least 15 wt. %calcium. In other embodiments, polyphosphate compositions containingcalcium as a cation contain at least 20 wt. % calcium. In otherembodiments, polyphosphate compositions containing calcium as a cationcontain at least 25 wt. % calcium. For example, in one embodiment, thepolyphosphate compositions containing calcium as a cation contain 7-25wt. % calcium. By way of further example, in one embodiment, thepolyphosphate compositions containing calcium as a cation contain 7-35wt. % calcium. In each of these embodiments, the calcium polyphosphatemay optionally contain magnesium and one or more of the other nutrientions described herein, or yet other compositions that may contribute tothe nutritional, material or handling characteristics of thepolyphosphate composition as a fertilizer.

Calcium polyphosphate fertilizers compositions of the present inventionmay optionally contain other components that contribute to thenutritional, material handling, or other characteristics of thefertilizer. For example, the calcium micronutrient fertilizer maycontain a water-soluble N—P—K macronutrient fertilizer that has beenblended or otherwise combined with the calcium polyphosphatecomposition. By way of further example, the calcium polyphosphatefertilizer may contain water-soluble or even water-insoluble nutrientcompounds that has been blended or otherwise combined with the calciumpolyphosphate composition. By way of further example, the calciumpolyphosphate fertilizer may contain organic materials like plantresidues that have been blended or otherwise combined with the calciumpolyphosphate composition to improve the material handlingcharacteristics of calcium polyphosphate fertilizer.

Calcium polyphosphate compositions may be prepared by combining acalcium source material, phosphoric acid and, optionally, one or moreadditional materials to form a reaction mixture and reacting thecomponents of the mixture to form the calcium polyphosphate. Thepolyphosphate is neutralized with calcium oxide or carbonate. Theoptional additional materials include, for example, magnesium and one ormore of the other nutrient ions described herein. The calcium sourcematerial may be any source of calcium that is compatible with thepolymerization process of the present invention. Such sources include,for example, calcium oxide, calcium carbonate, limestone, rock phosphate(apatite), calcium sulfate and calcium chloride.

Magnesium Polyphosphate Compositions

In one embodiment, the polyphosphate composition of the presentinvention comprises magnesium as a cation. In general, polyphosphatecompositions containing magnesium as a cation contain at least 7 wt. %magnesium. Typically, polyphosphate compositions containing magnesium asa cation contain at least 10 wt. % magnesium. In certain embodiments,polyphosphate compositions containing magnesium as a cation contain atleast 13 wt. % magnesium. In certain embodiments, polyphosphatecompositions containing magnesium as a cation contain at least 15 wt. %magnesium. In other embodiments, polyphosphate compositions containingmagnesium as a cation contain at least 20 wt. % magnesium. In otherembodiments, polyphosphate compositions containing magnesium as a cationcontain at least 25 wt. % magnesium. By way of further example, in oneembodiment, the polyphosphate compositions containing calcium as acation contain 7-35 wt. % magnesium. In each of these embodiments, themagnesium polyphosphate may optionally contain calcium and one or moreof the other nutrient ions described herein, or yet other compositionsthat may contribute to the nutritional, material or handlingcharacteristics of the polyphosphate composition as a fertilizer.

Magnesium polyphosphate fertilizers of the present invention mayoptionally contain other components that contribute to the nutritional,material handling, or other characteristics of the polyphosphatecomposition. For example, the magnesium micronutrient composition maycontain a water-soluble N—P—K macronutrient fertilizer that has beenblended or otherwise combined with the magnesium polyphosphatecomposition. By way of further example, the magnesium polyphosphatecomposition may contain water-soluble or even water-insoluble nutrientcompounds that has been blended or otherwise combined with the magnesiumpolyphosphate composition. By way of further example, the magnesiumpolyphosphate composition may contain organic materials like plantresidues that have been blended or otherwise combined with the magnesiumpolyphosphate composition to improve the material handlingcharacteristics of the composition.

Magnesium polyphosphate compositions may be prepared by combining amagnesium source material, phosphoric acid and, optionally, one or moreadditional materials to form a reaction mixture and reacting thecomponents of the mixture to form the magnesium polyphosphate. Themagnesium polyphosphate is neutralized with a basic magnesium sourcethat may include magnesium oxide and magnesium carbonate. The optionaladditional materials include, for example, calcium and one or more ofthe other nutrient ions described herein. The magnesium source materialmay be any source of magnesium that is compatible with thepolymerization process of the present invention. Such sources include,for example, magnesium oxide, magnesium carbonate, magnesite, magnesiumsulfate, and magnesium chloride.

Polyphosphate Fertilizers Containing Two Alkaline Earth Metal Ions

As noted, the polyphosphate may contain one or more alkaline earth metaland one or more nutrient ions. In general fertilizers that contain twoalkaline earth metals contain at least 7 wt. % alkaline earth metals,more typically at least 10 wt. % of alkaline earth metals. Additionally,the alkaline earth metals may be present in any of the concentrationsrecited herein in connection with the calcium polyphosphate fertilizersand magnesium polyphosphate fertilizers. For example, the fertilizer maycontain 7-35 wt. % calcium and/or 7-35 wt. % magnesium. By way offurther example, the fertilizer may contain 7-25 wt. % calcium and/or7-25 wt. % magnesium. In addition, the fertilizer may optionallycomprise one or more of the nutrient ions such as one or more ofpotassium, ammonium, sodium, zinc, iron, manganese, copper, boron,molybdenum, selenium, iodine and cobalt.

For certain applications, it is preferred that the alkaline earth metalpolyphosphate contains a combination of nutrient ions. In one suchembodiment, the alkaline earth metals polyphosphate contains potassiumas nutrient ion. For example, in one such embodiment, the potassiumconstitutes at least 0.01 wt. % of the alkaline earth metalspolyphosphate composition. By way of further example, in one suchembodiment, the potassium constitutes at least 2 wt. % of the alkalineearth metals polyphosphate composition. By way of further example, inone such embodiment, the potassium constitutes at least 10 wt. % of thealkaline earth metals polyphosphate composition. By way of furtherexample, in one such embodiment, the potassium constitutes at least 20wt. % of the alkaline earth metals polyphosphate composition.

For other applications it is preferred that the alkaline earth metalpolyphosphate contain ammonium as nutrient ion. For example, in one suchembodiment, the ammonium constitutes at least 0.01 wt. % of the alkalineearth metal polyphosphate composition. By way of further example, in onesuch embodiment, the ammonium constitutes at least 4 wt. % of thealkaline earth metal polyphosphate composition. By way of furtherexample, in one such embodiment, the ammonium constitutes at least 10wt. % of the alkaline earth metal polyphosphate composition. By way offurther example, in one such embodiment, the ammonium constitutes 4-15wt. % of the alkaline earth metal polyphosphate composition.

For other applications it is preferred that the alkaline earth metalpolyphosphate contains zinc as nutrient ion. For example, in one suchembodiment, the zinc constitutes at least 0.01 wt. % of the alkalineearth metal polyphosphate composition. By way of further example, in onesuch embodiment, the zinc constitutes less than 9 wt. % of the alkalineearth metal polyphosphate composition. By way of further example, in onesuch embodiment, the zinc constitutes less than 5 wt. % of the alkalineearth metal polyphosphate composition. By way of further example, in onesuch embodiment, the zinc constitutes less than 2 wt. % of the alkalineearth metal polyphosphate composition.

For other applications it is preferred that the alkaline earth metalpolyphosphate contains iron as nutrient ion. For example, in one suchembodiment, the iron constitutes at least 0.01 wt. % of the alkalineearth metal polyphosphate composition. By way of further example, in onesuch embodiment, the iron constitutes less than 6 wt. % of the alkalineearth metal polyphosphate composition. By way of further example, in onesuch embodiment, the iron constitutes less than 3 wt. % of the alkalineearth metal polyphosphate composition. By way of further example, in onesuch embodiment, the iron constitutes less than 1 wt. % of the alkalineearth metal polyphosphate composition.

For other applications it is preferred that the alkaline earth metalpolyphosphate contains manganese as nutrient ion. For example, in onesuch embodiment, the manganese constitutes at least 0.01 wt. % of thealkaline earth metal polyphosphate composition. By way of furtherexample, in one such embodiment, the manganese constitutes less than 5wt. % of the alkaline earth metal polyphosphate composition. By way offurther example, in one such embodiment, the manganese constitutes lessthan 2 wt. % of the alkaline earth metal polyphosphate composition. Byway of further example, in one such embodiment, the manganeseconstitutes less than 1 wt. % of the alkaline earth metal polyphosphatecomposition.

For other applications it is preferred that the alkaline earth metalpolyphosphate contains copper as nutrient ion. For example, in one suchembodiment, the copper constitutes at least 0.01 wt. % of the alkalineearth metal polyphosphate composition. By way of further example, in onesuch embodiment, the copper constitutes less than 5 wt. % of thealkaline earth metal polyphosphate composition. By way of furtherexample, in one such embodiment, the copper constitutes less than 2 wt.% of the alkaline earth metal polyphosphate composition. By way offurther example, in one such embodiment, the copper constitutes lessthan 1 wt. % of the alkaline earth metal polyphosphate composition.

For other applications it is preferred that the alkaline earth metalpolyphosphate contains boron as nutrient ion. For example, in one suchembodiment, the boron constitutes at least 0.01 wt. % of the alkalineearth metal polyphosphate composition. By way of further example, in onesuch embodiment, the boron constitutes less than 5 wt. % of the alkalineearth metal polyphosphate composition. By way of further example, in onesuch embodiment, the boron constitutes less than 2 wt. % of the alkalineearth metal polyphosphate composition. By way of further example, in onesuch embodiment, the boron constitutes less than 1 wt. % of the alkalineearth metal polyphosphate composition.

For other applications it is preferred that the alkaline earth metalpolyphosphate contains selenium as nutrient ion. For example, in onesuch embodiment, the selenium constitutes at least 0.01 wt. % of thealkaline earth metal polyphosphate composition. By way of furtherexample, in one such embodiment, the selenium constitutes less than 5wt. % of the alkaline earth metal polyphosphate composition. By way offurther example, in one such embodiment, the selenium constitutes lessthan 2 wt. % of the alkaline earth metal polyphosphate composition. Byway of further example, in one such embodiment, the selenium constitutesless than 1 wt. % of the alkaline earth metal polyphosphate composition

For other applications it is preferred that the alkaline earth metalpolyphosphate contain one or more of the nutrient ions disclosed herein.For example, in one embodiment the micronutrient metal polyphosphate maycontain less than 5 wt. % zinc and less than 2 wt. % boron. By way offurther example, in one embodiment the alkaline earth metalpolyphosphate may contain less than 3 wt. % zinc and less than 2 wt. %boron. By way of further example, in one embodiment the micronutrientmetal polyphosphate may contain less than 2 wt. % zinc and less than 0.2wt. % boron.

For other applications it is preferred that the alkaline earth metalpolyphosphate contain potassium, zinc, iron and manganese as nutrients.For example, in one such embodiment, the potassium, zinc, iron andmanganese, in combination, constitute less than 20 wt. % of the alkalineearth metal polyphosphate composition. By way of further example, in onesuch embodiment, the potassium, zinc, iron and manganese, incombination, constitute less than 10 wt. % of the alkaline earth metalpolyphosphate composition. By way of further example, in one suchembodiment, the potassium, zinc, iron and manganese, in combination,constitute less than 5 wt. % of the alkaline earth metal polyphosphatecomposition

Micronutrient Metal Polyphosphates

In general, the micronutrient metal polyphosphates of the presentinvention may be polymerized to various degrees. As previously discussedin connection with the polyphosphate compositions, for example, theaverage chain length (number average) may be in the range of about 1.5and 30 phosphate units (phosphorus atoms) per chain. In one embodiment,the average chain length (number average) is about 2 to 20 phosphateunits (phosphorus atoms) per chain. In general, it is preferred that thechain length be at the shorter end of the range. For example, in certainembodiments it is preferred that the average chain length (numberaverage) be between 5 and 8 phosphate units (phosphorus atoms) perchain.

Advantageously, the micronutrient metal polyphosphates of the presentinvention are water-insoluble. That is, the micronutrient metalpolyphosphates do not appreciably dissolve in water at room temperature(25° C.) water and neutral pH; for example, the micronutrient metalpolyphosphates will not release more than 15% of their micronutrientmetals in water within 10 minutes, and preferably within an hour. Themicronutrient metal polyphosphates, however, dissolve relatively rapidlyat room temperature in dilute acids such as 2 wt. % citric acid and0.005M diethylenetriaminepentaacetic acid (DTPA). In addition, theextent of dissolution in a one hour period in dilute acids such as 2 wt.% citric acid and 0.005M DTPA at room temperature is a substantialfraction of the extent of dissolution in significantly stronger acidssuch as 0.1N HCl acid at room temperature. For example, the extent ofdissolution in dilute acids such as 2 wt. % citric acid and 0.005M DTPAwill typically be at least 50% of the extent of dissolution in 0.1N HClin a one-hour period at room temperature. In certain preferredembodiments, the extent of dissolution in a one hour period in diluteacids such as 2 wt. % citric acid and 0.005M DTPA at room temperaturewill be at least 60% of the extent of dissolution in significantlystronger acids such as 0.1N HCl in a one-hour period at roomtemperature. In certain more preferred embodiments, the extent ofdissolution in a one hour period in dilute acids such as 2 wt. % citricacid and 0.005M DTPA at room temperature will be at least 70% of theextent of dissolution in significantly stronger acids such as 0.1 N HClin a one-hour period at room temperature. In certain more preferredembodiments, the extent of dissolution in a one hour period in diluteacids such as 2 wt. % citric acid and 0.005M DTPA at room temperaturewill be at least 90% of the extent of dissolution in significantlystronger acids such as 0.1 N HCl in a one-hour period at roomtemperature. In certain more preferred embodiments, the extent ofdissolution in a 30 minute period in dilute acids such as 6.9 wt. %citric acid at room temperature will be at least 70% of the extent ofdissolution in significantly stronger acids such as 0.1 N HCl in a 30minutes period at room temperature. In certain more preferredembodiments, the extent of dissolution in a one hour period in diluteacids such as 6.9 wt. % citric acid at room temperature will be at least80% of the extent of dissolution in significantly stronger acids such as0.1N HCl in a 30 minutes period at room temperature. In certain morepreferred embodiments, the extent of dissolution in a one hour period indilute acids such as 6.9 wt. % citric acid at room temperature will beat least 90% of the extent of dissolution in significantly strongeracids such as 0.1 N HCl in a 30 minutes period at room temperature.

In certain embodiments, zinc polyphosphates of the present invention areparticularly soluble in dilute acids. For example, within ten minutes atroom temperature, micronutrient metal polyphosphates containing zinc asthe only primary micronutrient will dissolve to the same extent indilute acids such as 2 wt. % citric acid and 0.005M DTPA as insignificantly stronger acids such as 0.1N HCl acid.

In addition to being soluble in dilute acids, the micronutrientpolyphosphate compositions of the present invention contain relativelylarge proportions of primary micronutrient metal concentrations. Onemanner of viewing this capacity is to compare the amount of primarymicronutrient metal in the polyphosphate composition to the amount ofphosphate (phosphorous atoms) in the polyphosphate composition.

In one embodiment, the micronutrient metal polyphosphate compositioncomprises zinc as the only primary micronutrient metal. In suchembodiments, the ratio of the equivalents of zinc to phosphorous in thezinc polyphosphate may be greater than 0.33:1, respectively. By way offurther example, in one embodiment in which zinc is the only primarymicronutrient metal, the ratio of the equivalents of zinc to phosphorousin the zinc polyphosphate may be greater than 0.35:1, respectively. Byway of further example, in one embodiment in which zinc is the onlyprimary micronutrient metal, the ratio of the equivalents of zinc tophosphorous in the zinc polyphosphate may be greater than 0.375:1,respectively. By way of further example, in one embodiment in which zincis the only primary micronutrient metal, the ratio of the equivalents ofzinc to phosphorous in the zinc polyphosphate may be greater than 0.4:1,respectively. In general, however, the upper limit of zinc is the amountthat would lead to the formation of the corresponding monohydrogenorthophosphate.

In another embodiment, the micronutrient metal polyphosphate compositioncomprises iron as the only primary micronutrient metal. In suchembodiments, the ratio of the equivalents of iron to phosphorous in theiron polyphosphate may be greater than 0.12:1, respectively. By way offurther example, the ratio of the equivalents of iron to phosphorous inthe iron polyphosphate may be greater than 0.15:1, respectively. By wayof further example, the ratio of the equivalents of iron to phosphorousin the iron polyphosphate may be greater than 0.2:1, respectively. Byway of further example, in one embodiment in which iron is the onlyprimary micronutrient metal, the ratio of the equivalents of iron tophosphorous in the iron polyphosphate may be greater than 0.25:1,respectively. By way of further example, in one embodiment in which ironis the only primary micronutrient metal, the ratio of the equivalents ofiron to phosphorous in the iron polyphosphate may be greater than 0.3:1,respectively. By way of further example, in one embodiment in which ironis the only primary micronutrient metal, the ratio of the equivalents ofiron to phosphorous in the iron polyphosphate may be greater than0.35:1, respectively. In general, however, the upper limit of iron isthe amount that would lead to the formation of the correspondingmonohydrogen orthophosphate.

In another embodiment, the micronutrient metal polyphosphate compositioncomprises manganese as the only primary micronutrient metal. In suchembodiments, the ratio of the equivalents of manganese to phosphorous inthe iron polyphosphate may be greater than 0.2:1, respectively. By wayof further example, in one embodiment in which manganese is the onlyprimary micronutrient metal, the ratio of the equivalents of manganeseto phosphorous in the manganese polyphosphate may be greater than0.25:1, respectively. Byway of further example, in one embodiment inwhich manganese is the only primary micronutrient metal, the ratio ofthe equivalents of manganese to phosphorous in the iron polyphosphatemay be greater than 0.3:1, respectively. By way of further example, inone embodiment in which manganese is the only primary micronutrientmetal, the ratio of the equivalents of manganese to phosphorous in themanganese polyphosphate may be greater than 0.35:1, respectively. By wayof further example, in one embodiment in which manganese is the onlyprimary micronutrient metal, the ratio of the equivalents of manganeseto phosphorous in the manganese polyphosphate may be greater than 0.4:1,respectively. In general, however, the upper limit of manganese is theamount that would lead to the formation of the correspondingmonohydrogen orthophosphate.

In another embodiment, the micronutrient metal polyphosphate compositioncomprises at least two of the primary micronutrients in micronutrientconcentrations. For example, as illustrated in the following examples,the micronutrient metal polyphosphate may comprise a combination ofprimary micronutrients selected from among the following combinations:(i) zinc and manganese; (ii) zinc and iron; (iii) zinc, iron andmanganese; (iv) zinc, iron, manganese and copper; and (v) iron,manganese and copper.

In one embodiment, the micronutrient metal polyphosphate compositioncomprises iron and manganese in micronutrient concentrations. Forexample, the ratio of the equivalents of iron and manganese (incombination) to phosphorous in the micronutrient metal polyphosphate maybe greater than 0.12:1, respectively. By way of further example, theratio of the equivalents of iron and manganese (in combination) tophosphorous in the micronutrient metal polyphosphate may be greater than0.15:1, respectively. By way of further example, the ratio of theequivalents of iron and manganese (in combination) to phosphorous in themicronutrient metal polyphosphate may be greater than 0.2:1,respectively. By way of further example, the ratio of the equivalents ofiron and manganese (in combination) to phosphorous in the micronutrientmetal polyphosphate may be greater than 0.25:1, respectively. By way offurther example, the ratio of the equivalents of iron and manganese (incombination) to phosphorous in the micronutrient metal polyphosphate maybe greater than 0.3:1, respectively. By way of further example, theratio of the equivalents of iron and manganese (in combination) tophosphorous in the micronutrient metal polyphosphate may be greater than0.35:1, respectively. In general, however, the upper limit of each ofthese metals is the amount that would lead to the formation of thecorresponding monohydrogen orthophosphate.

In one embodiment, the micronutrient metal polyphosphate compositioncomprises iron, manganese and copper in micronutrient concentrations.For example, the ratio of the equivalents of iron, manganese and copper(in combination) to phosphorous in the micronutrient metal polyphosphatemay be greater than 0.15:1, respectively. By way of further example, theratio of the equivalents of iron, manganese and copper (in combination)to phosphorous in the micronutrient metal polyphosphate may be greaterthan 0.2:1, respectively. By way of further example, the ratio of theequivalents of iron, manganese and copper (in combination) tophosphorous in the micronutrient metal polyphosphate may be greater than0.25:1, respectively. By way of further example, the ratio of theequivalents of iron, manganese and copper (in combination) tophosphorous in the micronutrient metal polyphosphate may be greater than0.3:1, respectively. By way of further example, the ratio of theequivalents of iron, manganese and copper (in combination) tophosphorous in the micronutrient metal polyphosphate may be greater than0.35:1, respectively. In general, however, the upper limit of each ofthese metals is the amount that would lead to the formation of thecorresponding monohydrogen orthophosphate.

In one embodiment, the micronutrient metal polyphosphate compositioncomprises zinc, iron, and manganese in micronutrient concentrations. Forexample, the ratio of the equivalents of zinc, iron, and manganese (incombination) to phosphorous in the micronutrient metal polyphosphate maybe greater than 0.2:1, respectively. By way of further example, theratio of the equivalents of zinc, iron, and manganese (in combination)to phosphorous in the micronutrient metal polyphosphate may be greaterthan 0.25:1, respectively. By way of further example, the ratio of theequivalents of zinc, iron, and manganese (in combination) to phosphorousin the micronutrient metal polyphosphate may be greater than 0.3:1,respectively. By way of further example, the ratio of the equivalents ofzinc, iron, and manganese (in combination) to phosphorous in themicronutrient metal polyphosphate may be greater than 0.35:1,respectively. In general, however, the upper limit of each of thesemetals is the amount that would lead to the formation of thecorresponding monohydrogen orthophosphate.

In one embodiment, the micronutrient metal polyphosphate compositioncomprises zinc, iron, manganese and copper in micronutrientconcentrations. For example, the ratio of the equivalents of zinc, iron,manganese and copper (in combination) to phosphorous in themicronutrient metal polyphosphate may be greater than 0.23:1,respectively. By way of further example, the ratio of the equivalents ofzinc, iron, manganese and copper (in combination) to phosphorous in themicronutrient metal polyphosphate may be greater than 0.25:1,respectively. By way of further example, the ratio of the equivalents ofzinc, iron, manganese and copper (in combination) to phosphorous in themicronutrient metal polyphosphate may be greater than 0.3:1,respectively. By way of further example, the ratio of the equivalents ofzinc, iron, manganese and copper (in combination) to phosphorous in themicronutrient metal polyphosphate may be greater than 0.35:1,respectively. In general, however, the upper limit of each of thesemetals is the amount that would lead to the formation of thecorresponding monohydrogen orthophosphate.

More generally, in certain embodiments the ratio of the equivalents ofthe primary micronutrient metals (in combination) to phosphorous in themicronutrient metal polyphosphate will be greater than 0.23:1,respectively. For example, in one embodiment in which micronutrientmetal polyphosphate comprises two or more primary micronutrient metals,the ratio of the equivalents of the primary micronutrient metals (incombination) to phosphorous in the micronutrient metal polyphosphatewill be greater than 0.25:1, respectively. By way of further example, inone embodiment in which micronutrient metal polyphosphate comprises twoor more primary micronutrient metals, the ratio of the equivalents ofthe primary micronutrient metals (in combination) to phosphorous in themicronutrient metal polyphosphate may be greater than 0.275:1,respectively. By way of further example, in one embodiment in whichmicronutrient metal polyphosphate comprises two or more primarymicronutrient metals, the ratio of the equivalents of the primarymicronutrient metals (in combination) to phosphorous in themicronutrient metal polyphosphate may be greater than 0.3:1,respectively. By way of further example, in one embodiment in whichmicronutrient metal polyphosphate comprises two or more primarymicronutrient metals, the ratio of the equivalents of the primarymicronutrient metals (in combination) to phosphorous in themicronutrient metal polyphosphate may be greater than 0.35:1,respectively. By way of further example, in one embodiment in whichmicronutrient metal polyphosphate comprises two or more primarymicronutrient metals, the ratio of the equivalents of the primarymicronutrient metals (in combination) to phosphorous in themicronutrient metal polyphosphate may be greater than 0.4:1,respectively. By way of further example, in one embodiment in whichmicronutrient metal polyphosphate comprises two or more primarymicronutrient metals, the ratio of the equivalents of the primarymicronutrient metals (in combination) to phosphorous in themicronutrient metal polyphosphate may be greater than 0.5:1,respectively. In general, however, the upper limit of each of thesemetals is the amount that would lead to the formation of thecorresponding monohydrogen orthophosphate.

Depending upon their composition, certain of the micronutrient metalpolyphosphates can be characterized by their X-ray diffractionreflections. For example, certain zinc polyphosphate compositions of thepresent invention, with or without iron, manganese, copper, boron ormolybdenum, may be characterized by having an X-ray diffractionreflection at one or more of the following positions: 8.72 (±0.09), 6.88(±0.07), 4.834 (±0.025), 4.710 (±0.025), 4.24 (±0.02), 4.20 (±0.02),3.969(±0.0175), 3.68 (±0.01), 3.58 (±0.01), 3.38 (±0.01), 2.848(±0.009), 2.585(±0.007), 2.430 (±0.007), 2.071 (±0.005), 1.934 (±0.004),1.80 (±0.003), 1.721 (±0.0029), 1.667 (±0.0028), 1.660 (±0.0027), 1.620(±0.0027), 1.615 (±0.0026), 1.594 (±0.0025), and 1.564 (±0.0024) Å. Inone embodiment, zinc polyphosphate compositions of the presentinvention, with or without iron, manganese, copper, boron or molybdenum,may be characterized by having an X-ray diffraction reflection at two ormore of said positions. In another embodiment, zinc polyphosphatecompositions of the present invention, with or without iron, manganese,copper, boron or molybdenum, may be characterized by having an X-raydiffraction reflection at three or more of said positions. In anotherembodiment, zinc polyphosphate compositions of the present invention,with or without iron, manganese, copper, boron or molybdenum, may becharacterized by having an X-ray diffraction reflection at four or moreof said positions. In another embodiment, zinc polyphosphatecompositions of the present invention, with or without iron, manganese,copper, boron or molybdenum, may be characterized by having an X-raydiffraction reflection at five or more of said positions.

Similarly, certain iron, manganese or copper polyphosphate compositionof the present invention may be characterized by having an X-raydiffraction reflection at one or more of the following positions:8.17(±0.09), 5.98 (±0.03), 5.16 (±0.03), 4.82 (±0.025), 4.52 (±0.025),4.27(±0.02), 4.16(±0.02), 3.48 (±0.01), 3.44 (±0.01), 2.87 (±0.009),2.85(±0.009), 2.59 (±0.007), 2.57 (±0.007), 2.52 (±0.007), 2.15(±0.005), 1.96 (±0.004), and 1.75 (±0.003) Å. In one embodiment, certainiron, manganese or copper polyphosphate composition of the presentinvention may be characterized by having an X-ray diffraction reflectionat two or more of said positions. In one embodiment, certain iron,manganese or copper polyphosphate composition of the present inventionmay be characterized by having an X-ray diffraction reflection at threeor more of said positions. In one embodiment, certain iron, manganese orcopper polyphosphate composition of the present invention may becharacterized by having an X-ray diffraction reflection at four or moreof said positions. In one embodiment, certain iron, manganese or copperpolyphosphate composition of the present invention may be characterizedby having an X-ray diffraction reflection at five or more of saidpositions.

As described elsewhere herein, the micronutrient metal polyphosphate isneutralized post-polymerization for improved material handlingcharacteristics. In general, it is preferred that the equilibrium pH ofan aqueous mixture of ten parts by weight of water at neutral pH and onepart by weight of the neutralized micronutrient metal polyphosphate beat least pH 2. More preferably, the equilibrium pH of an aqueous mixtureof ten parts by weight of water at neutral pH and one part by weight ofthe neutralized micronutrient metal polyphosphate be at least pH 3.Still more preferably, the equilibrium pH of an aqueous mixture of tenparts by weight of water at neutral pH and one part by weight of theneutralized micronutrient metal polyphosphate be at least pH 4. Stillmore preferably, the equilibrium pH of an aqueous mixture of ten partsby weight of water at neutral pH and one part by weight of theneutralized micronutrient metal polyphosphate be at least pH 5. Incertain embodiments, the equilibrium pH of an aqueous mixture of tenparts by weight of water at neutral pH and one part by weight of theneutralized micronutrient metal polyphosphate be at least pH 6. Forexample, in one embodiment, the equilibrium pH of an aqueous mixture often parts by weight of water at neutral pH and one part by weight of theneutralized micronutrient metal polyphosphate will be in the range of pH5-8.

In general, the micronutrient metal polyphosphate is preferably a solid,free-flowing particulate material. Particle size is not narrowlycritical but is generally preferably in the range of about 80 mesh toabout 150 mesh. Still preferably the particle size is in the range of150 mesh to 300 mesh. Still preferably the particle size is in less than300 mesh.

Cobalt Micronutrient Fertilizers

In one embodiment, the micronutrient fertilizer of the present inventioncomprises cobalt as a micronutrient. In general, fertilizers containingcobalt as a micronutrient contain at least 0.1 wt. % cobalt. Typically,fertilizers containing cobalt as a micronutrient contain at least 1 wt.% cobalt. In certain embodiments, fertilizers containing cobalt as amicronutrient contain at least 2 wt. % cobalt. In other embodiments,fertilizers containing cobalt as a micronutrient contain at least 3 wt.% cobalt. For example, in one embodiment, the fertilizers containingcobalt as a micronutrient contain 1-5 wt. % cobalt. In each of theseembodiments, the cobalt micronutrient fertilizer may optionally containone or more of the other primary nutrients described herein, one or moreof the secondary micronutrients described herein, other macronutrientsor micronutrients, or yet other compositions that may contribute to thenutritional, material or handling characteristics of the fertilizer.

Cobalt micronutrient fertilizers compositions of the present inventioncontain, as a component thereof, a micronutrient metal polyphosphatecomposition of the present invention, containing cobalt as amicronutrient. Such cobalt micronutrient fertilizer compositions mayoptionally contain other components that contribute to the nutritional,material handling, or other characteristics of the fertilizer. Forexample, the cobalt micronutrient fertilizer may contain a water-solubleN—P—K macronutrient fertilizer that has been blended or otherwisecombined with the cobalt polyphosphate composition. By way of furtherexample, the cobalt micronutrient fertilizer may contain water-solubleor even water-insoluble micronutrient compounds that has been blended orotherwise combined with the cobalt polyphosphate composition. By way offurther example, the cobalt micronutrient fertilizer may contain organicmaterials like plant residues that have been blended or otherwisecombined with the cobalt polyphosphate composition to improve thematerial handling characteristics of the cobalt micronutrientfertilizer.

Cobalt polyphosphate compositions may be prepared by combining a cobaltsource material, phosphoric acid (preferably containing no more than 60%P₂O₅), and, optionally, one or more additional materials to form areaction mixture and reacting the components of the mixture to form thecobalt polyphosphate. The optional additional materials include, forexample, one or more of the other primary micronutrients describedherein, one or more of the secondary micronutrients described herein andother macronutrient or micronutrient compositions desirably included inthe polyphosphate composition. The cobalt source material may be anysource of cobalt that is compatible with the polymerization process ofthe present invention. Such sources include, for example, cobaltousoxide cobaltic oxide, cobalt sulfate, and cobalt chloride.

Chromium Micronutrient Fertilizers

In one embodiment, the micronutrient fertilizer of the present inventioncomprises chromium as a micronutrient. In general, fertilizerscontaining chromium as a micronutrient contain at least 0.1 wt. %chromium. Typically, fertilizers containing chromium as a micronutrientcontain at least 1 wt. % chromium. In certain embodiments, fertilizerscontaining chromium as a micronutrient contain at least 2 wt. %chromium. In certain embodiments, fertilizers containing chromium as amicronutrient contain at least 3 wt. % chromium. In other embodiments,fertilizers containing chromium as a micronutrient contain at least 5wt. % chromium. For example, in one embodiment, the fertilizerscontaining chromium as a micronutrient contain 3-7 wt. % chromium. Ineach of these embodiments, the chromium micronutrient fertilizer mayoptionally contain one or more of the other primary nutrients describedherein, one or more of the secondary micronutrients described herein,other macronutrients or micronutrients, or yet other compositions thatmay contribute to the nutritional, material or handling characteristicsof the fertilizer.

Chromium micronutrient fertilizers compositions of the present inventioncontain, as a component thereof, a micronutrient metal polyphosphatecomposition of the present invention, containing chromium as amicronutrient. Such chromium micronutrient fertilizer compositions mayoptionally contain other components that contribute to the nutritional,material handling, or other characteristics of the fertilizer. Forexample, the chromium micronutrient fertilizer may contain awater-soluble N—P—K macronutrient fertilizer that has been blended orotherwise combined with the chromium polyphosphate composition. By wayof further example, the chromium micronutrient fertilizer may containwater-soluble or even water-insoluble micronutrient compounds that hasbeen blended or otherwise combined with the chromium polyphosphatecomposition. By way of further example, the chromium micronutrientfertilizer may contain organic materials like plant residues that havebeen blended or otherwise combined with the chromium polyphosphatecomposition to improve the material handling characteristics of thechromium micronutrient fertilizer.

Chromium polyphosphate compositions may be prepared by combining achromium source material, phosphoric acid (preferably containing no morethan 60% P₂O₅), and, optionally, one or more additional materials toform a reaction mixture and reacting the components of the mixture toform the chromium polyphosphate. The optional additional materialsinclude, for example, one or more of the other primary micronutrientsdescribed herein, one or more of the secondary micronutrients describedherein and other macronutrient or micronutrient compositions desirablyincluded in the polyphosphate composition. The chromium source materialmay be any source of chromium that is compatible with the polymerizationprocess of the present invention. Such sources include, for example,chromium (III) oxides, chromium (VI) oxide, chromium(III) sulfate,chromium(III) chloride, and dichromate salts.

Copper Micronutrient Fertilizers

In one embodiment, the micronutrient fertilizer of the present inventioncomprises copper as a micronutrient. In general, fertilizers containingcopper as a micronutrient contain at least 0.1 wt. % copper. Typically,fertilizers containing copper as a micronutrient contain at least 1 wt.% copper. In certain embodiments, fertilizers containing copper as amicronutrient contain at least 5 wt. % copper. In other embodiments,fertilizers containing copper as a micronutrient contain at least 10 wt.% copper. For example, in one embodiment, the fertilizers containingcopper as a micronutrient contain 14-20 wt. % copper. In each of theseembodiments, the copper micronutrient fertilizer may optionally containone or more of the other primary nutrients described herein, one or moreof the secondary micronutrients described herein, other macronutrientsor micronutrients, or yet other compositions that may contribute to thenutritional, material or handling characteristics of the fertilizer.

Copper micronutrient fertilizers compositions of the present inventioncontain, as a component thereof, a micronutrient metal polyphosphatecomposition of the present invention, containing copper as amicronutrient. Such copper micronutrient fertilizer compositions mayoptionally contain other components that contribute to the nutritional,material handling, or other characteristics of the fertilizer. Forexample, the copper micronutrient fertilizer may contain a water-solubleN—P—K macronutrient fertilizer that has been blended or otherwisecombined with the copper polyphosphate composition. By way of furtherexample, the copper micronutrient fertilizer may contain water-solubleor even water-insoluble micronutrient compounds that has been blended orotherwise combined with the copper polyphosphate composition. By way offurther example, the copper micronutrient fertilizer may contain organicmaterials like plant residues that have been blended or otherwisecombined with the copper polyphosphate composition to improve thematerial handling characteristics of the copper micronutrientfertilizer.

Copper polyphosphate compositions may be prepared by combining a coppersource material, phosphoric acid (preferably containing no more than 60%P₂O₅), and, optionally, one or more additional materials to form areaction mixture and reacting the components of the mixture to form thecopper polyphosphate. The optional additional materials include, forexample, one or more of the other primary micronutrients describedherein, one or more of the secondary micronutrients described herein andother macronutrient or micronutrient compositions desirably included inthe polyphosphate composition. The copper source material may be anysource of copper that is compatible with the polymerization process ofthe present invention. Such sources include, for example, cupriccarbonate, cupric hydroxide, cupric hydroxide carbonate, cupric sulfate,cupric chloride, and cupric oxide.

Manganese Micronutrient Fertilizers

In one embodiment, the micronutrient fertilizer of the present inventioncomprises manganese as a micronutrient. In general, fertilizerscontaining manganese as a micronutrient contain at least 0.1 wt. %manganese. Typically, fertilizers containing manganese as amicronutrient contain at least 1 wt. % manganese. In certainembodiments, fertilizers containing manganese as a micronutrient containat least 5 wt. % manganese. In other embodiments, fertilizers containingmanganese as a micronutrient contain at least 8 wt. % manganese. Forexample, in one embodiment, the fertilizers containing manganese as amicronutrient contain 10-20 wt. % manganese. In each of theseembodiments, the manganese micronutrient fertilizer may optionallycontain one or more of the other primary nutrients described herein, oneor more of the secondary micronutrients described herein, othermacronutrients or micronutrients, or yet other compositions that maycontribute to the nutritional, material or handling characteristics ofthe fertilizer.

Manganese micronutrient fertilizers compositions of the presentinvention contain, as a component thereof, a micronutrient metalpolyphosphate composition of the present invention, containing manganeseas a micronutrient. Such manganese micronutrient fertilizer compositionsmay optionally contain other components that contribute to thenutritional, material handling, or other characteristics of thefertilizer. For example, the manganese micronutrient fertilizer maycontain a water-soluble N—P—K macronutrient fertilizer that has beenblended or otherwise combined with the manganese polyphosphatecomposition. By way of further example, the manganese micronutrientfertilizer may contain water-soluble or even water-insolublemicronutrient compounds that has been blended or otherwise combined withthe manganese polyphosphate composition. By way of further example, themanganese micronutrient fertilizer may contain organic materials likeplant residues that have been blended or otherwise combined with themanganese polyphosphate composition to improve the material handlingcharacteristics of the manganese micronutrient fertilizer.

Manganese polyphosphate compositions may be prepared by combining amanganese source material, phosphoric acid (preferably containing nomore than 60% P₂O₅), and, optionally, one or more additional materialsto form a reaction mixture and reacting the components of the mixture toform the manganese polyphosphate. The optional additional materialsinclude, for example, one or more of the other primary micronutrientsdescribed herein, one or more of the secondary micronutrients describedherein and other macronutrient or micronutrient compositions desirablyincluded in the polyphosphate composition. The manganese source materialmay be any source of manganese that is compatible with thepolymerization process of the present invention. Such sources include,for example, manganous carbonate, manganous oxide, manganese dioxide,manganous sulfate, and manganous chloride.

Zinc Micronutrient Fertilizers

In one embodiment, the micronutrient fertilizer of the present inventioncomprises zinc as a micronutrient. In general, fertilizers containingzinc as a micronutrient contain at least 0.1 wt. % zinc. Typically,fertilizers containing zinc as a micronutrient contain at least 1 wt. %zinc. In certain embodiments, fertilizers containing zinc as amicronutrient contain at least 10 wt. % zinc. In other embodiments,fertilizers containing zinc as a micronutrient contain 20-30 wt. % zinc.For example, in one embodiment, the fertilizers containing zinc as amicronutrient contain 20-25 wt. % zinc. By way of further example, inone embodiment, the fertilizers containing zinc as a micronutrientcontain 24-30 wt. % zinc. In each of these embodiments, the zincmicronutrient fertilizer may optionally contain one or more of the otherprimary nutrients described herein, one or more of the secondarymicronutrients described herein, other macronutrients or micronutrients,or yet other compositions that may contribute to the nutritional,material or handling characteristics of the fertilizer.

Zinc micronutrient fertilizers compositions of the present inventioncontain, as a component thereof, a micronutrient metal polyphosphatecomposition of the present invention, containing zinc as amicronutrient. Such zinc micronutrient fertilizer compositions mayoptionally contain other components that contribute to the nutritional,material handling, or other characteristics of the fertilizer. Forexample, the zinc micronutrient fertilizer may contain a water-solubleN—P—K macronutrient fertilizer that has been blended or otherwisecombined with the zinc polyphosphate composition. By way of furtherexample, the zinc micronutrient fertilizer may contain water-soluble oreven water-insoluble micronutrient compounds that has been blended orotherwise combined with the zinc polyphosphate composition. By way offurther example, the zinc micronutrient fertilizer may contain organicmaterials like plant residues that have been blended or otherwisecombined with the zinc polyphosphate composition to improve the materialhandling characteristics of the zinc micronutrient fertilizer.

Zinc polyphosphate compositions may be prepared by combining a zincsource material, phosphoric acid (preferably containing no more than 60%P₂O₅), and, optionally, one or more additional materials to form areaction mixture and reacting the components of the mixture to form thezinc polyphosphate. The optional additional materials include, forexample, one or more of the other primary micronutrients describedherein, one or more of the secondary micronutrients described herein andother macronutrient or micronutrient compositions desirably included inthe polyphosphate composition. The zinc source material may be anysource of zinc that is compatible with the polymerization process of thepresent invention. Such sources include, for example, zinc oxide, zincmetal, zinc ash, zinc sulfate, zinc carbonate and zinc chloride.

Iron Micronutrient Fertilizers

In one embodiment, the micronutrient fertilizer of the present inventioncomprises iron as a micronutrient. In general, fertilizers containingiron as a micronutrient contain at least 0.1 wt. % iron. Typically,fertilizers containing iron as a micronutrient contain at least 1 wt. %iron. In certain embodiments, fertilizers containing iron as amicronutrient contain at least 3 wt. % iron. In other embodiments,fertilizers containing iron as a micronutrient contain at least 4 wt. %iron. For example, in one embodiment, the fertilizers containing iron asa micronutrient contain 5-15 wt. % iron. In each of these embodiments,the iron micronutrient fertilizer may optionally contain one or more ofthe other primary nutrients described herein, one or more of thesecondary micronutrients described herein, other macronutrients ormicronutrients, or yet other compositions that may contribute to thenutritional, material or handling characteristics of the fertilizer.

Iron micronutrient fertilizers compositions of the present inventioncontain, as a component thereof, a micronutrient metal polyphosphatecomposition of the present invention, containing iron as amicronutrient. Such iron micronutrient fertilizer compositions mayoptionally contain other components that contribute to the nutritional,material handling, or other characteristics of the fertilizer. Forexample, the iron micronutrient fertilizer may contain a water-solubleN—P—K macronutrient fertilizer that has been blended or otherwisecombined with the iron polyphosphate composition. By way of furtherexample, the iron micronutrient fertilizer may contain water-soluble oreven water-insoluble micronutrient compounds that has been blended orotherwise combined with the iron polyphosphate composition. By way offurther example, the iron micronutrient fertilizer may contain organicmaterials like plant residues that have been blended or otherwisecombined with the iron polyphosphate composition to improve the materialhandling characteristics of the iron micronutrient fertilizer.

Iron polyphosphate compositions may be prepared by combining an ironsource material, phosphoric acid (preferably containing no more than 60%P₂O₅), and, optionally, one or more additional materials to form areaction mixture and reacting the components of the mixture to form theiron polyphosphate. The optional additional materials include, forexample, one or more of the other primary micronutrients describedherein, one or more of the secondary micronutrients described herein andother macronutrient or micronutrient compositions desirably included inthe polyphosphate composition. The iron source material may be anysource of iron that is compatible with the polymerization process of thepresent invention. Such sources include, for example, goethite, hematiteiron hydroxide, ferrous oxide, ferric sulfate, ferrous sulfate, ferricchloride, and ferric sulfate.

Fertilizers Containing Two or More Micronutrients

As noted, the micronutrient metal polyphosphate may contain two or moreprimary micronutrients, one or more primary micronutrients and one ormore secondary micronutrients. In general fertilizers that contain twoor more primary micronutrients contain at least 0.1 wt. % primarynutrients, more typically at least 1 wt. % of each of the primarymicronutrients. Additionally, the primary micronutrient metals may bepresent in any of the concentrations recited herein in connection withthe cobalt micronutrient fertilizers, chromium micronutrientfertilizers, copper micronutrient fertilizers, iron micronutrientfertilizers, manganese micronutrient fertilizers, and zinc micronutrientfertilizers. For example, the fertilizer may contain 1-5 wt. % cobalt,1-20 wt. % copper, 1-7 wt. % chromium, 1-15 wt. % iron, 1-20 wt. %manganese, and/or 1-30 wt. % zinc. In addition, the fertilizer mayoptionally comprise one or more of the secondary micronutrients such asone or more of boron, molybdenum and selenium. By way of furtherexample, in one such composition contains less than 30 wt. % of boron,chromium, cobalt, copper, iodine, iron, manganese, molybdenum, selenium,sulfur and zinc, in combination.

For certain applications, it is preferred that the micronutrient metalpolyphosphate contain a combination of primary micronutrient metals. Inone such embodiment, the micronutrient metal polyphosphate containszinc, iron, and manganese as micronutrient metals. For example, in onesuch embodiment, the zinc, iron and manganese, in combination,constitute at least 5 wt. % of the micronutrient metal polyphosphatecomposition. By way of further example, in one such embodiment, thezinc, iron and manganese, in combination, constitute at least 12 wt. %of the micronutrient metal polyphosphate composition.

For other applications it is preferred that the micronutrient metalpolyphosphate contain zinc, iron, manganese and copper as micronutrientmetals. For example, in one such embodiment, the zinc, iron, manganese,and copper, in combination, constitute at least 10 wt. % of themicronutrient metal polyphosphate composition. By way of furtherexample, in one such embodiment, the zinc, iron, manganese, and copper,in combination, constitute at least 14 wt. % of the micronutrient metalpolyphosphate composition. By way of further example, in one suchembodiment, the zinc, iron, manganese, and copper, in combination,constitute about 15-25 wt. % of the micronutrient metal polyphosphatecomposition. Individually, zinc may constitute about 5-15 wt %, iron mayconstitute about 3-5 wt. %, manganese may constitute about 1-2 wt. % andcopper may constitute about 0.5-1 wt. % of the composition.

For other applications it is preferred that the micronutrient metalpolyphosphate contain iron and manganese as micronutrient metals. Forexample, in one such embodiment, the iron and manganese, in combination,constitute at least 5 wt. % of the micronutrient metal polyphosphatecomposition. By way of further example, in one such embodiment, the ironand manganese, in combination, constitute at least 10 wt. % of themicronutrient metal polyphosphate composition. Individually, forexample, iron may constitute about 3-10 wt % and manganese mayconstitute about 3-10 wt. % of the composition.

For other applications it is preferred that the micronutrient metalpolyphosphate contain iron, manganese and copper as micronutrientmetals. For example, in one such embodiment, the iron, manganese, andcopper, in combination, constitute at least 6 wt. % of the micronutrientmetal polyphosphate composition. By way of further example, in one suchembodiment, the iron, manganese, and copper, in combination, constituteat least 12 wt. % of the micronutrient metal polyphosphate composition.

For other applications it is preferred that the micronutrient metalpolyphosphate contain one or more of the primary micronutrients and oneor more of the secondary micronutrients disclosed herein. For example,in one embodiment the micronutrient metal polyphosphate may contain atleast 2 wt. % zinc and at least 0.1 wt. % boron. By way of furtherexample, in one embodiment the micronutrient metal polyphosphate maycontain at least 22 wt. % zinc and at least 2 wt. % boron.

For other applications it is preferred that the micronutrient metalpolyphosphate contain zinc, iron, manganese and molybdenum asmicronutrients. For example, in one such embodiment, the zinc, iron, andmanganese, in combination, constitute at least 5 wt. % and molybdenumconstitutes at least 0.01 wt. % of the micronutrient metal polyphosphatecomposition. By way of further example, in one such embodiment, thezinc, iron, and manganese, in combination, constitute at least 13 wt. %and molybdenum constitutes at least 0.3 wt. % of the micronutrient metalpolyphosphate composition.

For other applications it is preferred that the micronutrient metalpolyphosphate contain zinc, iron, manganese, copper and boron asmicronutrients. For example, in one such embodiment, the zinc, iron,copper, and manganese, in combination, constitute at least 5 wt. % andboron constitutes at least 0.05 wt. % of the micronutrient metalpolyphosphate composition. By way of further example, in one suchembodiment, the zinc, iron, copper, and manganese, in combination,constitute at least 14 wt. % and boron constitutes at least 0.9 wt. % ofthe micronutrient metal polyphosphate composition.

Methods of Producing Polyphosphate Compositions

In an illustrative embodiment, the polyphosphate compositions areproduced by heating alkaline earth metal containing compounds such asoxides, carbonates, hydroxides, phosphates, sulfates or combinationsthereof, with phosphoric acid, and optionally nutrient compounds andoptionally water. In an embodiment, heating alkaline earth metalcontaining compounds such as metal oxides, metal carbonates, orcombinations thereof, with phosphoric acid, and optionally water,produces polyphosphates. In an alternative embodiment, the polyphosphatecompositions are produced by pre-heating phosphoric acid and optionallywater to between about 60° C. and 140° C., or to between 60° C. and 200°C. and then combining alkaline earth metal containing compounds such asoxides, carbonates, hydroxides or combinations thereof and optionallynutrient compounds. In another alternative embodiment, the polyphosphatecompositions are produced by heating alkaline earth metal containingcompounds such as oxides, carbonates, hydroxides or combinationsthereof, with phosphoric acid, and optionally water then addingoptionally nutrient compounds and continuing the heating. In anembodiment, the polymerization step does not include a condensing agentsuch as urea. In an embodiment the heating is not continued till thestage when the polyphosphate becomes solid. In this embodiment, heatingis done only till the stage that the polyphosphate remains a liquid.

After the alkaline earth metal compound is added to the phosphoric acidand optionally water, optionally sulfuric acid, boric acid, borax,molybdic acid or selenic acid or their salts may be added and themixture may be heated to between about 70° C. and about 160° C.,alternatively between about 80° C. and about 120° C., alternativelybetween about 80° C. and about 200° C., alternatively to about 105° C.,and alternatively to about 110° C. Then, the nutrient ion compound andoptionally sulfuric acid. boric acid, borax, molybdic acid or selenicacid or a salt thereof may be added to the mixture of alkaline earthmetal compound and phosphoric acid. Contemporaneously with the additionof nutrient ion compound, water is preferably added to the mixture. Themixture of the alkaline earth metal compound, phosphoric acid,optionally nutrient ion compound, and water is preferably heated tobetween about 70° C. and about 160° C., alternatively between about 80°C. and about 120° C., alternatively between about 80° C. and about 200°C., alternatively to about 105° C., alternatively to about 110° C., andpolymerization occurs.

Preferably, during the polymerization stage, for any alkaline earthmetal ion M²⁺, the molar ratio of phosphorous to metal is greater thanabout 1.5:1. Thus, for producing a calcium polyphosphate, the molarratio of phosphorous to calcium taken for polymerization is more than2:1, preferably about 2.2:1, or preferably about 2.5:1, or preferablyabout 3:1. Alternately, for producing a calcium-magnesium polyphosphate,the molar ratio of phosphorous to calcium and magnesium (incombination), taken for polymerization is more than 2:1, preferablyabout 2.7:1. Alternately, for producing a calcium-magnesiumpolyphosphate, the molar ratio of phosphorous to calcium and magnesium(in combination), taken for polymerization is more than 2:1, preferablyabout 3:1

In an alternative embodiment, for any optional nutrient metal ionM^(n+), where n+ is the valance of the metal ion, excess phosphoric acidhas to be taken where the molar ratio of phosphorous to metal is greaterthan about n:1. For example, if the metal ion has a valence of +3, themolar ratio of phosphorous to the metal is greater than 3:1 (e.g., 5moles or more of phosphorous for every mole of metal).

The polymerization step may be terminated when the product is soluble inabout 6.9 wt % citric acid, two weight percent citric acid or 0.1 normalhydrochloric acid. Without wishing to be bound by the theory, theproduct is preferably heated until just before it becomes insoluble in0.1 wt. % citric acid or 0.01 normal hydrochloric acid, asover-polymerization may cause insolubilization in acid and reduce theavailability of the nutrients to plants.

The polyphosphate composition product may be poured out of the reactorand cooled. When the product temperature reaches below about 90° C.,water may be added to increase the product's fluidity; additionally, thepolyphosphate composition product may be stirred to further enhanceand/or maintain fluidity. The polyphosphate composition product may alsobe neutralized with a neutralizing base, dried and ground to a powder.

Preferable neutralizing bases include magnesium oxides, magnesiumcarbonates, calcium oxides, calcium carbonates, ammonium hydroxides,ammonium carbonates, sodium hydroxides, sodium carbonates, potassiumhydroxides, potassium carbonates and combinations thereof. Bases aremixed with water prior to their use for neutralizing the polyphosphate.Without wishing to be bound by the theory, addition of water to the basereduces lumping of the neutralized polyphosphate. Preferably, thepolyphosphate composition product is ground to an average particle sizeof less than about 200 mesh, alternatively less than about 150 mesh,alternatively less than about 100 mesh.

Having described the invention in detail, it will be apparent thatmodifications and variations are possible without departing the scope ofthe invention defined in the appended claims. The following non-limitingexamples are provided to further illustrate the present invention andthose of skill in the art should, in light of the present disclosure,appreciate that many changes can be made in the specific embodimentsthat are disclosed and still obtain a like or similar result withoutdeparting from the spirit and scope of the invention.

EXAMPLES

The following methods were used to characterize the materials in theexamples below:

Total cation content: 50 milligrams of sample was dissolved in 3milliliters of concentrated sulphuric acid by heating for a few minutes.The solution was diluted and filtered. Cations in solution were analysedby atomic absorption spectroscopy

Maximum adsorption by urea/DAP/MAP/SSP: A weighed amount ofpolyphosphate fertilizer was mixed with a weighed amount ofurea/DAP/MAP/SSP granules. This was mixed thoroughly and then sievedthrough 80 mesh BS. The amount of polyphosphate that came out of thesieve was weighed.

Total phosphorus content: 50 milligrams of sample was fused with sodiumhydroxide in a nickel crucible and taken into solution with water.Phosphorus was determined by the molybdenum blue color method. (SoilChemical Analysis, M L Jackson, 1973, Prentice Hall, New Delhi).

Number Average Chain Length: The titrimetric method reported by VanWazer was followed for the determination of number average chain lengthexcluding ortho using the equation: [{2(total P−orthophosphateP)}/{endgroup P−orthophosphate P}] (Van Wazer, J. R. 1966. Phosphorusand its compounds, Vol. 1. Interscience, New York, N.Y.; Ray S K,Chandra P K, Varadachari C and Ghosh K (1998)). For removingmicronutrient metal cation interferences prior to titrimetricdetermination of polyphosphate chain length, the sample was dissolved in0.1 N HCl and stirred with a cation exchange resin in H-form. Thesupernatant solution which was free of cations (except hydrogen) wastitrated for polyphosphate chain length by the method of Van Wazer J. R.1966 referred above).

For solubilities, mesh size of less than 150 mesh was used.

Water solubility: 50 milligrams of sample was placed in a conical flaskand 50 milliliters of water was added to it. This was placed in a rotaryshaker for 30 minutes, then filtered washed and made to volume. Cationsin solution were analysed by atomic absorption spectroscopy. Amount ofcation solubilized was expressed as a percentage of total cationdetermined as described above.

0.1N HCl solubility: Solubility of the samples in 0.1N HCl wasdetermined as described above for citrate solubility.

Citrate solubility: 25 milligrams of samples was placed in a conicalflask and 50 milliliters of 0.1 wt. %, 0.2 wt. % citric acid, 2 wt %citric acid or 6.9 wt % citric acid was added to it. It was placed in arotary shaker for 20, 30 minutes or 60 minutes. It was then filteredwashed and made to volume. Cations in solution were determined asdescribed in the paragraph above. Solubilities in citrate are expressedas a percentage of that dissolved by 0.1N HCl.

DTPA solubility: Solubility of the samples in 0.005 M DTPA wasdetermined as described above for citrate solubility. Solubilities inDTPA are expressed as a percentage of that dissolved by 0.1N HCl.

EDTA solubility: Solubility of the samples in 0.005 M EDTA wasdetermined as described above for citrate solubility. Solubilities incitrate are expressed as a percentage of that dissolved by 0.1 N HCl.

0.01N HCl solubility: Solubility of the samples in 0.01N HCl wasdetermined as described above for citrate solubility. Solubilities incitrate are expressed as a percentage of that dissolved by 0.1N HCl.

pH: pH of the fertilizers was recorded on a pH meter in a stirredsuspension containing 1 gram of fertilizer powder in 10 milliliterswater.

X-ray diffraction: XRD of the powdered sample was recorded in a X-raydiffractometer using Cu K_(a) radiation at a scan rate of 2° 2 theta perminute.

Example 1 Zinc Fertilizer Coated on Urea A. Production of ZincFertilizer

The fertilizer was produced from phosphoric acid (58.4% P₂O₅) and zincoxide (50% Zn, 6.8% Fe, 6% Mg) in the molar ratio Zn:P=1:2.5. Commercialgrade phosphoric acid (58.4% P₂O₅), 348 grams, was placed in aborosilicate beaker. In another beaker, 600 milliliters of water wastaken and to it 150 grams of commercial grade zinc oxide (50% Zn) wasadded and stirred to form a slurry. The phosphoric acid was heated in anoil bath till its temperature reached 100° C. Then the slurry of zincoxide was added to the phosphoric acid with stirring. The reaction wasexothermic, and the temperature was raised to about 70° C. due toexothermic heat of the reaction. The beaker was further heated withstirring for about 20 minutes until the temperature of the liquid was103° C. The beaker was then taken out of the heating unit and allowed tocool to around 90° C. Then a slurry of 105 grams of magnesium oxide (54%Mg) in 700 milliliters of water was added to it with stirring whereupona white suspension was formed. This was mixed well in a blender anddried in a tray drier at 70° C. The dried material was powdered in apulverizer to pass through 150 mesh.

The product included 11.2 weight percent zinc, 8.4 weight percentmagnesium, 1.5 weight percent iron and 13.2 weight percent phosphorous.It had a pH of 5.4. The ratio of equivalent of Zn to equivalent of P was0.27. In 2 weight percent citric acid the product released 96.8% oftotal zinc and 94% of total magnesium. In 0.005 molar DTPA the productreleased 96.1% of total zinc and 92.2% of total magnesium with respectto the total in 0.1N HCl. In water 0.32% of total Zn, 4.76% of totalmagnesium and 7.9% of total P was solubilized. Dissolution in weaklyacidic solution of pH 4 was 0.69% of total zinc and 4.7% of totalmagnesium. In a weakly alkaline solution, 0.46% of total zinc and 4.62%of total magnesium was dissolved. In 0.02M EDTA at pH 4.65, 95.8% oftotal Zn and 94.8% of total magnesium was solubilized. In 1N ammoniumcitrate at pH 8.5, 98.5% of total Zn and 96.3% of total magnesium wassolubilized. X-ray diffraction diagram for the product shows peaks at26.5, 20.75, 9.61, 9.096, 6.7, 6.37, 5.857, 5.422, 4.736, 4.536, 4.287,3.91, 3.597, 3.496, 3.405, 3.244, 3.195, 3.167, 3.091, 2.975, 2.855,2.643, 2.537, 2.434, 2.416, 2.373, 2.321, 2.265, 2.218, 2.148, 2.076,2.033, 1.982, 1.964, 1.93, 1.92, 1.8325, 1.7991, 1.753, 1.6198, 1.5932,1.5483 Å.

B. Coating on Urea

100 grams of urea granules (1-3 mm, 46% N) was weighed into a dry glassjar and 4 grams of the zinc fertilizer (of 150 mesh size) was added toit. It was shaken by hand to mix the contents thoroughly. The zincfertilizer adhered to the urea and did not sediment at the bottom. Theproduct mainly contained 0.43 weight percent zinc, 0.51 weight percentphosphorus, 0.32 weight percent magnesium and 44.2 weight percentnitrogen. When the urea was added to water, the zinc fertilizerparticles immediately dispersed and urea dissolved. This forms aconvenient method of applying the zinc fertilizer in the field. It alsoenriches the urea with micronutrient.

A maximum of 4.5 grams of this zinc fertilizer can be coated on 100grams of urea.

Example 2 Zinc Fertilizer Coated on MAP (Mono Ammonium Phosphate) A.Production of Zinc Fertilizer

The fertilizer of example 1 was used.

B. Coating on MAP (Method I)

100 grams of MAP granules (2-4 mm, 22.7% P, 11% N) was weighed into adry glass jar and 1.5 grams of the zinc fertilizer (of 150 mesh size)was added to it. It was shaken by hand to mix the contents thoroughly.The product mainly contained 0.16 weight percent zinc, 22.6 weightpercent phosphorus, 0.12 weight percent magnesium and 10.8 weightpercent nitrogen. When the product was added to water, the zincfertilizer particles immediately dispersed. This forms a convenientmethod of applying the zinc fertilizer in the field. It also enrichesthe MAP with micronutrient.

A maximum of 1.8 grams of this zinc fertilizer can be coated on 100grams of MAP.

C. Coating on MAP (Method II)

100 grams of MAP granules (2-4 mm) was weighed into a tray and 20 gramsof the zinc fertilizer (of 150 mesh size) was added to it. It wasmoistened with 10 milliliters water and dried with a hot air blower (at60° C.) with constant mixing of the mass. The zinc fertilizer coated onto the surface of MAP. The product contained 1.87 weight percent zinc,1.4 weight percent magnesium, 21.1 weight percent phosphorus and 9.2weight percent nitrogen. When the product was added to water, the zincfertilizer particles dispersed in about 30 minutes. This forms aconvenient method of applying the zinc fertilizer in the field. It alsoenriches the MAP with micronutrient.

Example 3 Zinc Fertilizer Coated on DAP A. Production of Zinc Fertilizer

The fertilizer of example 1 was used.

B. Coating on DAP (Method I)

100 grams of DAP granules (1-4 mm, 18% N, 17.9% P) was weighed into adry glass jar and 3.5 grams of the zinc fertilizer (of 150 mesh size)was added to it. It was shaken by hand to mix the contents thoroughly.The zinc fertilizer adhered to the DAP and did not sediment at thebottom. The product contained 0.38 weight percent zinc, 0.28 weightpercent magnesium, 17.7 weight percent phosphorus and 17.4 weightpercent nitrogen. When the DAP was added to water, the zinc fertilizerparticles immediately dispersed and DAP dissolved. This forms aconvenient method of applying the zinc fertilizer in the field. It alsoenriches the DAP with micronutrient.

A maximum of 4 grams of this zinc fertilizer can be coated on 100 gramsof DAP.

C. Coating on DAP (Method II)

100 grams of DAP granules (as described in B above) was weighed into atray and its surface was moistened with about 8 milliliters water. Then20 grams of the zinc fertilizer (of 150 mesh size) was added to it andmixed thoroughly. The mass was dried with a hot air drier (at 60° C.)with constant mixing of the mass. The zinc fertilizer coated on to thesurface of DAP. The coating was firm and did not come off when rubbedbetween the fingers. The product contained 1.87 weight percent zinc, 1.4weight percent magnesium, 17.1 weight percent phosphorus and 15 weightpercent nitrogen. When the product was added to water, the zincfertilizer particles dispersed over 30 minutes. This forms a convenientmethod of applying the zinc fertilizer in the field. It also enrichesthe DAP with micronutrient.

Example 4 Zinc Fertilizer Coated on SSP A. Production of Zinc Fertilizer

The fertilizer of example 1 was used.

B. Coating on SSP

100 grams of SSP granules (2-4 mm, 7% P) was weighed into a dry glassjar and 5 grams of the zinc fertilizer (of 150 mesh size) was added toit. It was shaken by hand to mix the contents thoroughly. The zincfertilizer adhered to the SSP and did not sediment at the bottom. Theproduct contained 0.5 weight percent zinc and 7.3 weight percentphosphorus. When the product was added to water, the particles dispersedin 5 minutes. This enriches the SSP with micronutrient and forms aconvenient carrier for the micronutrient.

C. Coating on SSP (Method II)

100 grams of SSP granules (2-4 mm, 7% P) was weighed into a tray and itssurface was moistened with about 10 milliliters water. Then 25 grams ofthe zinc fertilizer (of 150 mesh size) was added to it and mixedthoroughly. The mass was dried with a hot air drier (at 60° C.) withconstant mixing of the mass. The zinc fertilizer coated on to thesurface of SSP. The product mainly contained 2.2 weight percent zinc,1.7 weight percent magnesium and 8.2 weight percent phosphorus. When theproduct was added to water, the particles dispersed in a 20 minutes.This enriches the SSP with micronutrient and forms a carrier for zincfertilizer application.

Example 5 Zinc Fertilizer Granulated A. Production of Zinc Fertilizer

The fertilizer of example 1 was used.

B. Granulation (Method I)

100 grams of zinc fertilizer powder (80 mesh) was mixed with 15 grams ofbentonite powder and granulated. The granules were hard and of goodquality. The product mainly contained 9.7 weight percent zinc, 7.3weight percent magnesium and 11.5 weight percent phosphorus. When theproduct was added to water, the particles dispersed in 10 minutes. Thisforms a convenient means of delivering the micronutrient.

C. Granulation (Method II)

100 grams of zinc fertilizer powder (80 mesh) was mixed with water andthen granulated. These granules are softer than in method B above. Theproduct contained 11.2 weight percent zinc, 13.2 weight percentphosphorus and 8.4 weight percent magnesium. When the product was addedto water, the particles dispersed in 5 minutes. This forms a means ofdelivering the micronutrient.

Example 6 Zinc Fertilizer Coated on Urea A. Production of ZincFertilizer Zn 200 3.058 p 158.4

The fertilizer was produced from green phosphoric acid (54% P₂O₅ andcontaining sludge) and zinc oxide (80% Zn) in the molar ratioZn:P=1:1.75. Commercial grade phosphoric acid (54% P₂O₅), 672 grams(with 50 milliliters of sludge), was placed in a borosilicate beaker.The beaker was then placed in a heated oil bath and heated with stirringfor 25 minutes until the temperature of the liquid was 120° C. Then 250grams of commercial grade zinc oxide (80% Zn) was added to the hotphosphoric acid. The reaction was exothermic, and the temperature wasraised to about 128° C. due to exothermic heat of the reaction. It wasfurther heated till its temperature reached 130° C. Then 100 millilitersof water was added to the and heating was continued for 15 minutes untilthe temperature of the liquid reached 119° C. The beaker was then takenout of the heating unit. When the liquid temperature cooled to 90° C., aslurry of magnesium oxide (120 grams) in 400 milliliters of water wasadded to it with stirring whereupon a white suspension was formed. Thiswas mixed well in a blender and dried in a tray drier at 70° C. Thedried material was powdered in a pulverizer to pass through 150 mesh.

The product included 22.3 weight percent zinc, 8.45 weight percentmagnesium, 7.24 weight percent calcium and 19.1 weight percentphosphorous. The ratio of equivalent of Zn to equivalent of P was 0.37.Number average chain length of the polyphosphate (excludingorthophosphate) was 4.76. Number average chain length of thepolyphosphate (including orthophosphate) was 2.17. It had anorthophosphate content of 19%. In 2 weight percent citric acid theproduct released 98.5% of total zinc, 93.4% of total magnesium and 88.4%of total magnesium. In 0.005 molar DTPA the product released 93.4% ofzinc, 90.1% of total magnesium and 87.7% of total calcium. In water0.47% of total Zn, 4.6% of total magnesium, 0.25% of total calcium and8.2% of total P was solubilized. Dissolution in weakly acidic solutionof pH 4 was 0.79% of total zinc, 0.57% of total calcium and 4.6% oftotal magnesium. In a weakly alkaline solution, 0.56% of total zinc, 1%of total calcium and 4.33% of total magnesium was dissolved. In 0.02MEDTA at pH 4.65, 92.4% of total Zn, 95.2% of total calcium and 90.5% oftotal magnesium was solubilized. In 1N ammonium citrate at pH 8.5, 93.5%of total Zn and 92.7% of total calcium and 92.6% of total magnesium wassolubilized. X-ray diffraction diagram for the product shows peaks at23.62, 16.58, 11.17, 8.936, 8.067, 7.603, 6.177, 6.077, 5.913, 5.762,5.627, 5.329, 5.245, 5.034, 4.913, 4.709, 4.559, 4.488, 4.399, 4.125,4.083, 3.993, 3.878, 3.789, 3.652, 3.561, 3.452, 3.381, 3.183, 3.125,3.069, 3.034, 2.949, 2.907, 2.845, 2.836, 2.787, 2.764, 2.712, 2.623,2.605, 2.576, 2.514, 2.47, 2.426, 2.402, 2.368, 2.331, 2.263, 2.217,2.152, 2.143, 2.1296, 2.0942, 1.9766, 1.9371, 1.9143, 1.8682, 1.8275,1.7982, 1.7894, 1.7554, 1.7166, 1.6956, 1.6339, 1.5913, 1.5546 Å.

B. Coating on Urea

The process was the same as described in Example 1 except that 10 gramsof the zinc fertilizer (of 150 mesh size) of this example was added toit. The product contained 2 weight percent zinc, 0.8 weight percentmagnesium, 0.66 weight percent calcium, 1.74 weight percent phosphorusand 41.8 weight percent nitrogen. When the urea was added to water, theparticles immediately dispersed and urea dissolved.

The maximum amount of zinc fertilizer that can be retained on the ureasurface is 19.5 grams per 100 grams of urea.

Example 7 Zinc Fertilizer Coated on MAP A. Production of Zinc Fertilizer

The fertilizer of example 6 was used.

B. Coating on MAP (Method I)

The process described in Example 2B was used except that 0.4 grams ofthe zinc fertilizer of the example 6 was added to it. The zincfertilizer adhered well to the urea and did not sediment at the bottom.The product contained 0.1 weight percent zinc, 0.1 weight percentphosphorus and 46 weight percent nitrogen. When the MAP was added towater, the particles immediately dispersed and urea dissolved.

A maximum of 0.4 grams of this zinc fertilizer can be coated on 100grams of urea.

C. Coating on MAP (Method II)

The process described in Example 2C was used except that 20 grams of thezinc fertilizer of the example 6 was added to it. The product contained3.72 weight percent zinc, 1.4 weight percent magnesium, 1.2 weightpercent calcium, 22.1 weight percent phosphorus and 9.2 weight percentnitrogen. When the product was added to water, the particles dispersedin about 30 minutes. This forms a convenient method of applying the zincfertilizer in the field. It also enriches the urea with micronutrient.

Example 8 Zinc Fertilizer Granulated with SSP A. Production of ZincFertilizer

The fertilizer of example 6 was used.

B. Granulation with SSP

100 grams of SSP powder (7% P) was mixed with 10 grams of the zincfertilizer (of 150 mesh size). Water was added to moisten it. It wasbroken into small lumps and dried. The dried granules of large size werebroken and sieved to obtain 2 mm granules. The product contained 2weight percent zinc and 8.1 weight percent phosphorus. When the productwas added to water, the particles dispersed in 60 minutes. The zincfertilizer acts as a binder to promote granulation of SSP. It alsoenriches the SSP with micronutrient and forms a convenient carrier forthe micronutrient.

Example 9 Zinc Fertilizer Coated on DAP A. Production of Zinc Fertilizer

The fertilizer of example 6 was used.

B. Coating on DAP (Method I)

The process described in Example 3B was used except that 5 grams of thezinc fertilizer of the example 6 was added to it. The product contained1 weight percent zinc, 0.4 weight percent magnesium, 0.34 weight percentcalcium, 18 weight percent phosphorus and 17.1 weight percent nitrogen.When the DAP was added to water, the particles immediately dispersed.This forms a convenient method of applying the zinc fertilizer in thefield. It also enriches the DAP with micronutrient.

A maximum of 5.5 grams of this zinc fertilizer can be coated on 100grams of DAP.

C. Coating on DAP (Method II)

The process described in Example 3C was used except that 20 grams of thezinc fertilizer of the example 6 was added to it. The product contained3.7 weight percent zinc, 1.4 weight percent magnesium, 1.2 weightpercent calcium, 18.1 weight percent phosphorus and 15 weight percentnitrogen. When the DAP was added to water, the particles dispersed inabout 45 minutes. The coating was firm and did not come off when rubbedbetween the fingers.

Example 10 Zinc Fertilizer Granulated with Mono Ammonium Phosphate (MAP)and its Use as a Granulating Agent A. Production of Zinc Fertilizer

The fertilizer of example 6 was used.

B. Granulation

100 grams of MAP (crystalline powder) was mixed with 20 grams of zincfertilizer powder and 8 milliliters of water and granulated by drying at60° C. Hard granules were formed. The product contained 3.7 weightpercent zinc, 1.4 weight percent magnesium, 1.2 weight percent calcium,22.1 weight percent phosphorus and 9.17 weight percent nitrogen. Whenthe product was added to water, the particles dispersed in 5 minutes.This forms a convenient means of granulating MAP and simultaneouslydelivering the micronutrient.

Example 11 Zinc Fertilizer Coated on Organic Granules C. Production ofZinc Fertilizer

The fertilizer of example 6 was used.

D. Granulation

100 grams of composted plant waste granules was mixed with 30 grams ofzinc fertilizer powder and 8 milliliters of water and granulated bydrying at 60° C. Hard granules were formed. The product contained mainly5.4 weight percent zinc, 4.9 weight percent phosphorus and 1.7 weightpercent nitrogen. When the product was added to water, the particlesdispersed in 5 minutes. This forms a convenient means of delivering themicronutrient.

Example 12 Zinc Fertilizer Coated on Seeds A. Production of ZincFertilizer

The fertilizer of example 6 was used except it was further ground tosize less than 300 mesh.

B. Coating on Seeds (Rice Seeds)

100 grams of rice seeds was weighed into a tray. In a beaker, 40milliliters of water was taken and 5 grams bentonite powder was added toit and stirred. To the bentonite slurry 25 grams of the zinc fertilizer(300 mesh) was added and stirred. The slurry was poured over the riceseeds and then dried with an air blower at 40° C. with constant mixing.The product is rice seed with 4.3 weight percent zinc, 1.6 weightpercent magnesium, 1.4 weight percent calcium, 3.7 weight percentphosphorus When the seeds were placed in water, the fertilizer dispersedimmediately. This forms a convenient method of applying the zincfertilizer in the field. It also enriches the DAP with micronutrient.

In an alternative method, the coating was produced by substitutingbentonite with 10 grams of organic plant waste compost.

Example 13 Zinc-Manganese Fertilizer Coated on Urea

The fertilizer of this example was produced from phosphoric acid, zincoxide, manganous oxide and magnesium oxide.

Phosphoric acid (green acid containing 54% P₂O₅ and sludge) 563 grams(with 50 milliliters of sludge), was placed in a borosilicate beaker.Then 100 grams of zinc oxide (80% Zn) was added to the phosphoric acidin the beaker, with stirring. The reaction was exothermic. The beakerwas placed in a heated oil bath and stirred for 10 minutes until thetemperature of the liquid was 90° C. Then 133.4 grams of manganous oxide(60% Mn) was made into a slurry with 800 milliliters of water and addedto the phosphoric acid-zinc oxide liquid with stirring. Further heatingwas done for 15 minutes until the temperature of the liquid reached 100°C. The beaker was then taken out of the heating unit and neutralized 55grams of magnesium oxide in 350 milliliters water. A white suspensionwas formed. This was mixed well in a blender and dried in a tray drierat 70° C. The dried material was powdered in a pulverizer to passthrough 150 mesh.

The product included 9.2 weight percent zinc, 9.4 weight percentmanganese, 7.6 weight percent magnesium, 8 weight percent calcium and16.2 weight percent phosphorous. The pH of this product was 4.1. Theratio of equivalent of Zn+Mn to equivalent of P was 0.4. Number averagechain length of the polyphosphate (excluding orthophosphate) was 5.1.Number average chain length of the polyphosphate (includingorthophosphate) was 1.62. It had an orthophosphate content of 33 wt %.In 2 weight percent citric acid the product released 97.8% of total zincand 97.7% of total manganese, 92.2% of total magnesium and 90.4% oftotal calcium. In 0.005 M DTPA the product released 96.3% of total zincand 95.4% of total manganese, 90.7% of total magnesium and 88.5% oftotal calcium. In water 1% of total Zn, 5.2% of total manganese, 5% oftotal magnesium, 0.5% of total calcium and 7.9% of total P wassolubilized. Dissolution in weakly acidic solution of pH 4 was 1.2% oftotal zinc, 5.4% of total manganese, 0.8% of total calcium and 5.1% oftotal magnesium. In a weakly alkaline solution of pH 8, 1.5% of totalzinc, 5.2% of total manganese, 1.3% of total calcium and 5% of totalmagnesium was dissolved. In 0.02M EDTA at pH 4.65, 95.6% of total Zn,94.6% of total manganese, 89.3% of total calcium and 87.1% of totalmagnesium was solubilized. In 1N ammonium citrate at pH 8.5, 97.3% oftotal Zn, 95.5% of total manganese, 91.3% of total calcium and 88.3% oftotal magnesium was solubilized. X-ray diffraction diagram for theproduct shows peaks at 23.9, 17.3, 14.2, 13.2, 8.97, 8.06, 6.29, 5.953,5.396, 5.132, 5.055, 4.936, 4.743, 4.622, 4.865, 4.152, 4.097, 3.944,3.896, 3.809, 3.67, 3.55, 3.459, 3.377, 3.241, 3.132, 3.068, 2.918,2.869, 2.832, 2.776, 2.731, 2.674, 2.655, 2.625, 2.592, 2.566, 2.533,2.405, 2.375, 2.34, 2.294, 2.25, 2.223, 2.215, 2.174, 2.153, 2.131,2.106, 1.969, 1.9454, 1.8729, 1.8458, 1.8355, 1.8199, 1.743, 1.7347,1.6682, 1.6449, 1.607, 1.5631, 1.5591 Å.

B. Coating on Urea

The process was the same as described in Example 1 except that 20 gramsof the zinc-manganese fertilizer (of 150 mesh size) of this example wasadded to it. The product contained 1.5 weight percent zinc, 1.6 weightpercent manganese, 1.3 weight percent magnesium, 1.3 weight percentcalcium, 2.7 weight percent phosphorus and 38.3 weight percent nitrogen.When the urea was added to water, the particles of micronutrientfertilizer immediately dispersed and urea dissolved.

This fertilizer can be coated to the maximum extent of 40 grams forevery 100 grams of urea.

Example 14 Zinc-Manganese Fertilizer Coated on DAP A. Production ofZinc-Manganese Fertilizer

The fertilizer of example 13 was used.

B. Coating on DAP (Method I)

The process was as described in Example 3B except that 5 grams of thezinc-manganese fertilizer of the example 13 was used. The productcontained 0.4 weight percent zinc, 0.4 weight percent manganese, 0.4weight percent magnesium, 0.4 weight percent calcium, 17.8 weightpercent phosphorus and 17.1 weight percent nitrogen. When the productwas added to water, the particles of micronutrient fertilizerimmediately dispersed.

This fertilizer can be coated to the maximum extent of 7 grams for every100 grams of DAP.

C. Coating on DAP (Method II)

The process described in Example 3C was used except that 20 grams of thezinc-manganese fertilizer of the example 13 was used. The productcontained 1.5 weight percent zinc, 1.6 weight percent manganese, 1.3weight percent magnesium, 1.3 weight percent calcium, 17.6 weightpercent phosphorus and 15 weight percent nitrogen. When added to waterthe micronutrient dispersed slowly over 60 minutes.

Example 15 Zinc-Manganese Fertilizer Coated on MAP A. Production ofZinc-Manganese Fertilizer

The fertilizer of example 13 was used.

B. Coating on MAP (Method I)

The process was as described in Example 2B except that 0.3 grams of thezinc-manganese fertilizer of the example 13 was used. The productcontained 0.27 weight percent zinc, 0.27 weight percent manganese, 0.22weight percent magnesium, 0.23 weight percent calcium, 22.5 weightpercent phosphorus and 10.7 weight percent nitrogen. When the productwas added to water, the particles immediately dispersed.

A maximum of 3.5 grams of this zinc-manganese fertilizer can be coatedon 100 grams of MAP.

C. Coating on MAP (Method II)

The process described in Example 2C was used except that 20 grams of thezinc fertilizer of the example 13 was added to it. The product contained1.5 weight percent zinc, 1.6 weight percent manganese, 1.3 weightpercent magnesium, 1.3 weight percent calcium, 21.6 weight percentphosphorus and 9.2 weight percent nitrogen. When the product was addedto water, the particles dispersed in about 30 minutes.

Example 16 Manganese Fertilizer Coated on Urea B. Production ofManganese Fertilizer

The fertilizer was produced from green phosphoric acid (54% P₂O₅ andcontaining sludge) and manganous oxide (60% Mn) in the molar ratioMn:P=1:1.5. Commercial grade phosphoric acid (54% P₂O₅), 437 grams (with25 milliliters of sludge), was placed in a borosilicate beaker and 220milliliters water was added to it. The beaker was then placed in aheated oil bath and heated 60° C. Then 194 grams of commercial grademanganous oxide (60.8% Mn) was mixed with 700 milliliters water and theslurry was added to the hot phosphoric acid. It was further heated forabout 20 minutes till its temperature reached 102° C. The beaker wasthen taken out of the heating unit. When the liquid temperature cooledto 90° C., a slurry of magnesium oxide (50 grams, 60% Mn) in 350milliliters of water was added to it with stirring whereupon a whitesuspension was formed. This was mixed well in a blender and dried in atray drier at 70° C. The dried material was powdered in a pulverizer topass through 150 mesh.

The product included 16.3 weight percent manganese, 8.3 weight percentmagnesium, 6.6 weight percent calcium and 15.8 weight percentphosphorous. The pH of a 10% suspension was 4.56. The ratio ofequivalent of Mn to equivalent of P was 0.39. In 2 weight percent citricacid the product released 95.6% of total manganese, 93.1% of totalmagnesium and 89.3% of total calcium. In 0.005 molar DTPA the productreleased 94.6% of total manganese, 90.6% of total magnesium and 86.3% oftotal calcium. In water 4.8% of total manganese, 4.6% of total magnesiumand 0.4% of total calcium and 8% of total P was solubilized. Dissolutionin weakly acidic solution of pH 4 was 4% of total manganese, 4.6% oftotal magnesium and 0.7% of total calcium. In a weakly alkalinesolution, 3.9% of total manganese, 1.2% of total calcium and 4.6% oftotal magnesium was dissolved. In 0.02M EDTA at pH 4.65, 93.4% of totalmanganese, 90.4% of total calcium and 90.3% of total magnesium wassolubilized. In 1N ammonium citrate at pH 8.5, 96.4% of total manganese,93% of total calcium and 94.5% of total magnesium was solubilized. X-raydiffraction diagram for the product shows peaks at 24, 11.9, 8.65, 8.06,7.42, 6.89, 6.49, 6.246, 5.945, 5.723, 5.383, 5.297, 4.694, 4.608,4.316, 4.221, 4.117, 3.978, 3.845, 3.789, 3.445, 3.263, 3.144, 3.04,2.97, 2.786, 2.728, 2.573, 2.549, 2.5, 2.353, 2.305, 2.1604, 2.1285,2.0924, 2.0436, 1.9025, 1.8463, 1.8244, 1.7994, 1.6811, 1.6731 Å.

B. Coating on Urea

The process was the same as described in Example 1 except that 10 gramsof the manganese fertilizer (of 150 mesh size) of this example was addedto it. The product contained 1.5 weight percent manganese, 0.73 weightpercent magnesium, 0.6 weight percent calcium, 1.4 weight percentphosphorus and 41.8 weight percent nitrogen. When the urea was added towater, the particles immediately dispersed and urea dissolved.

The maximum amount of manganese fertilizer that can be retained on theurea surface is 30 grams per 100 grams of urea.

Example 17 Manganese Fertilizer Coated on MAP C. Production of ZincFertilizer

The fertilizer of example 16 was used.

D. Coating on MAP (Method I)

The process described in Example 2B was used except that 2 grams of themanganese fertilizer of the example 16 was added to it. The productcontained 0.32 weight percent manganese, 0.16 weight percent magnesium,0.13 weight percent calcium, 22.5 weight percent phosphorus and 10.8weight percent nitrogen. When the MAP was added to water, themicronutrient fertilizer particles immediately dispersed.

A maximum of 2 grams of this zinc fertilizer can be coated on 100 gramsof urea.

C. Coating on MAP (Method II)

The process described in Example 2C was used except that 15 grams of themanganese fertilizer of the example 16 was added to it. The productcontained 2.1 weight percent manganese, 1.1 weight percent magnesium,0.86 weight percent calcium, 21.8 weight percent phosphorus and 9.6weight percent nitrogen. When the product was added to water, theparticles dispersed in about 30 minutes.

Example 18 Manganese Fertilizer Coated on DAP C. Production of ManganeseFertilizer

The fertilizer of example 16 was used.

D. Coating on DAP (Method I)

The process described in Example 3B was used except that 1 grams of themanganese fertilizer of the example 16 was added to it. The productcontained 0.16 weight percent manganese, 0.08 weight percent magnesium,0.06 weight percent calcium, 17.9 weight percent phosphorus and 17.8weight percent nitrogen. When the DAP was added to water, the particlesimmediately dispersed.

A maximum of 1.6 grams of this manganese fertilizer can be coated on 100grams of DAP.

C. Coating on DAP (Method II)

The process described in Example 3C was used except that 20 grams of themanganese fertilizer of the example 16 was added to it. The productcontained 2.7 weight percent manganese, 1.4 weight percent magnesium,1.1 weight percent calcium, 17.6 weight percent phosphorus and 15 weightpercent nitrogen. When the DAP was added to water, the particlesdispersed in about 45 minutes. The coating was firm and did not come offwhen rubbed between the fingers.

Example 19 Manganese Fertilizer Coated on Urea C. Production ofManganese Fertilizer

The fertilizer was produced from phosphoric acid (58.4% P₂O₅), manganousoxide (60% Mn) and magnesium oxide (54% Mg) in the molar ratioMn:P=1:1.5. Commercial grade phosphoric acid (58.4% P₂O₅), 437 grams,was placed in a borosilicate beaker and 220 milliliters water was addedto it. The beaker was then placed in a heated oil bath and heated for 10minutes 60° C. Then 220 grams of commercial grade manganous oxide (60%Mn) was mixed with 200 milliliters water and the slurry was added to thehot phosphoric acid. A further 750 milliliters of water was added. Thereaction was exothermic and liquid temperature increased to 80° C. Itwas further heated for about 20 minutes till its temperature reached100° C. The beaker was then taken out of the heating unit. When theliquid temperature cooled to 80° C., a slurry of magnesium oxide (82grams) in 150 milliliters of water was added to it with stirringwhereupon a white suspension was formed. This was mixed well in ablender and dried in a tray drier at 70° C. The dried material waspowdered in a pulverizer to pass through 150 mesh.

The product included 16.8 weight percent manganese, 6.4 weight percentmagnesium and 14.3 weight percent phosphorous. The ratio of equivalentof Mn to equivalent of P was 0.44. The pH of this product in a 10%suspension was 6.76. In 2 weight percent citric acid the productreleased 96.7% of total manganese and 94.2% of total magnesium. In 0.005molar DTPA the product released 92.2% of total manganese and 91.1% oftotal magnesium. In water 2.9% of total manganese, 6% of total magnesiumand 8.4% of total P was solubilized. Dissolution in weakly acidicsolution of pH 4 was 3.2% of total manganese, 5.9% of total magnesium.In a weakly alkaline solution, 3.4% of total manganese and 6.1% of totalmagnesium was dissolved. In 0.02M EDTA at pH 4.65, 98% of totalmanganese and 96.7% of total magnesium was solubilized. In 1N ammoniumcitrate at pH 8.5, 89.7% of total manganese and 94.2% of total magnesiumwas solubilized. X-ray diffraction diagram for the product shows peaksat 20.3, 17.8, 16.45, 15.16, 12.42, 10.15, 8.97, 7.91, 6.77, 6.356,5.867, 5.791, 5.308, 4.954, 4.813, 4.652, 4.471, 3.829, 3.654, 3.446,3.328, 3.26, 3.22, 3.173, 3.128, 3.063, 3.024, 2.969, 2.931, 2.918,2.895, 2.857, 2.789, 2.679, 2.215, 2.179, 2.131, 2.095, 1.993, 1.926,1.889, 1.878, 1.852, 1.829, 1.729, 1.719, 1.6354, 1.6163, 1.5991 Å.

B. Coating on Urea

The process was the same as described in Example 1 except that 10 gramsof the manganese fertilizer (of 150 mesh size) of this example was addedto it. The product contained 1.5 weight percent manganese, 0.58 weightpercent magnesium, 1.3 weight percent phosphorus and 41.8 weight percentnitrogen. When the urea was added to water, the particles immediatelydispersed and urea dissolved.

The maximum amount of manganese fertilizer that can be retained on theurea surface is 20 grams per 100 grams of urea.

Example 20 Manganese Fertilizer Coated on MAP A. Production of ZincFertilizer

The fertilizer of example 19 was used.

B. Coating on MAP (Method I)

The process described in Example 2B was used except that 1 gram of themanganese fertilizer of the example 19 was added to it. The productcontained 0.17 weight percent manganese, 0.06 weight percent magnesium,22.6 weight percent phosphorus and 10.9 weight percent nitrogen. Whenthe MAP was added to water, the particles immediately dispersed and ureadissolved.

A maximum of 1.2 grams of this manganese fertilizer can be coated on 100grams of urea.

C. Coating on MAP (Method II)

The process described in Example 2C was used except that 10 grams of themanganese fertilizer of the example 19 was added to it. The productcontained 1.53 weight percent manganese, 0.58 weight percent magnesium,21.9 weight percent phosphorus and 10 weight percent nitrogen. When theproduct was added to water, the particles dispersed in about 30 minutes.

Example 21 Manganese Fertilizer Coated on DAP E. Production of ManganeseFertilizer

The fertilizer of example 19 was used.

F. Coating on DAP (Method I)

The process described in Example 3B was used except that 1 gram of themanganese fertilizer of the example 19 was added to it. The productcontained 0.17 weight percent manganese, 0.06 weight percent magnesium,17.9 weight percent phosphorus and 17.8 weight percent nitrogen. Whenthe DAP was added to water, the particles immediately dispersed.

A maximum of 2 grams of this manganese fertilizer can be coated on 100grams of DAP.

C. Coating on DAP (Method II)

The process described in Example 3C was used except that 10 grams of themanganese fertilizer of the example 19 was added to it. The productcontained 1.5 weight percent manganese, 0.58 weight percent magnesium,17.6 weight percent phosphorus and 16.4 weight percent nitrogen. Whenthe DAP was added to water, the particles dispersed in about 45 minutes.The coating was firm and did not come off when rubbed between thefingers.

Example 22 Iron-Manganese Fertilizer Coated on Urea

The fertilizer of this example was produced from phosphoric acid,magnetite (Fe₃O₄, 69% Fe), manganous oxide (60% Mn) and magnesium oxide(54% Mg).

Commercial grade phosphoric acid (58.5% P₂O₅), 199 grams, was placed ina borosilicate beaker and mixed with 100 milliliters water. This wasplaced in an oil bath and heated to 60° C. Then a slurry of 100 grams ofmanganous oxide in 350 milliliters water was made and this was added tothe phosphoric acid. Heating was continued till the temperature of theliquid reached 101° C. In another beaker, 769 grams of phosphoric acidwas taken. Magnetite (174 grams) was made into a slurry with 200milliliters water. This slurry was added to the phosphoric acid in thebeaker. A further 150 milliliters water was added. The reaction was veryexothermic, and the temperature was raised to about 90° C. Thismagnetite containing liquid was then added to the manganous oxidecontaining liquid. A further 450 milliliters water was added. The beakerwas then placed in an oil bath and heated again till the liquidtemperature reached 62° C. The beaker was then taken out of the heatingunit. Then 180 grams of magnesium oxide was made into a slurry with 2liters water. This was added to the liquid with stirring. Then it wasdried at 60° C. and powdered in a pulverizer to pass through 150 mesh.

The product included 10.4 weight percent iron, 5.3 weight percentmanganese, 5.9 weight percent magnesium and 22 weight percentphosphorous. The ratio of equivalent of Zn to equivalent of P was 0.35.The pH of this product was 4.24. In 2 weight percent citric acid theproduct released 89.1% of total iron, 96.2 weight percent of totalmanganese, 93.5 weight percent of total magnesium. In 0.005 molar DTPAthe product released 93.6% of total iron, 97.6 weight percent of totalmanganese, 90.4 weight percent of total magnesium. In water 0.12% oftotal iron, 3.98 weight percent of total manganese, 5.7 weight percentof total magnesium and 8.3% of total P was solubilized. Dissolution inweakly acidic solution of pH 4 was 0.02% of total iron, 4.5 weightpercent of total manganese, 6.2 weight percent of total magnesium. In aweakly alkaline solution, 0.04% of total iron, 4.65 weight percent oftotal manganese, 6.34 weight percent of total magnesium was dissolved.In 0.02M EDTA at pH 4.65, 88.7% of total iron, 90.6 weight percent oftotal manganese, 94.2 weight percent of total magnesium was solubilized.In 1N ammonium citrate at pH 8.5, 85.4 weight percent of total iron,88.6 weight percent of total manganese, 95.3 weight percent of totalmagnesium was solubilized. X-ray diffraction diagram for the productshows peaks at 24.9, 18.9, 14.4, 11.8, 8.7, 8.3, 7.0, 6.82, 6.71, 6.57,5.91, 5.357, 5.056, 4.72, 4.469, 4.229, 4.137, 3.856, 3.671, 3.459,3.341, 3.261, 3.196, 3.087, 3.030, 2.797, 2.728, 2.704, 2.632, 2.605,2.596, 2.514, 2.375, 2.198, 2.138, 2.108, 2.062, 2.031, 1.990, 1.932,1.902, 1.863, 1.846, 1.835, 1.825, 1.794, 1.773, 1.76, 1.746, 1.727,1.685, 1.604, 1.586 Å.

B. Coating on Urea

100 grams of urea was weighed into a dry glass jar and 15 grams of theiron-manganese fertilizer (of 150 mesh size) was added to it. It wasshaken by hand to mix the contents thoroughly. The iron-manganesefertilizer adhered to the urea and did not sediment at the bottom. Theproduct contained 1.3 weight percent iron, 0.69 weight percentmanganese, 0.77 weight percent magnesium, 2.9 weight percent phosphorusand 40 weight percent nitrogen. When the urea was added to water, theparticles immediately dispersed and urea dissolved.

This fertilizer can be coated to the maximum extent of 30 grams forevery 100 grams of urea.

Example 23 Iron-Manganese Fertilizer Coated on MAP A. Production of ZincFertilizer

The fertilizer of example 6 was used.

B. Coating on MAP (Method I)

The process described in Example 2B was used except that 1 gram of theiron-manganese fertilizer of the example 22 was added to it. The productcontained 0.1 weight percent iron, 0.05 weight percent manganese, 0.06weight percent magnesium, 22.7 weight percent phosphorus and 10.9 weightpercent nitrogen. When the product was added to water, the micronutrientfertilizer particles immediately dispersed.

A maximum of 1.2 grams of this iron-manganese fertilizer can be coatedon 100 grams of MAP.

C. Coating on MAP (Method II)

The process described in Example 2C was used except that 5 grams of theiron-manganese fertilizer of the example 22 was added to it. The productcontained 0.5 weight percent iron, 0.25 weight percent manganese, 0.28weight percent magnesium, 22.7 weight percent phosphorus and 10.5 weightpercent nitrogen. When the product was added to water, the particlesdispersed in about 30 minutes.

Example 24 Iron-Manganese Fertilizer Coated on DAP A. Production ofManganese Fertilizer

The fertilizer of example 22 was used.

B. Coating on DAP (Method I)

The process described in Example 3B was used except that 5 grams of theiron-manganese fertilizer of the example 22 was added to it. The productcontained 0.5 weight percent iron, 0.25 weight percent manganese, 0.28weight percent magnesium, 18.1 weight percent phosphorus and 17.1 weightpercent nitrogen. When the DAP was added to water, the particlesimmediately dispersed. This forms a convenient method of applying thezinc fertilizer in the field. It also enriches the DAP withmicronutrient.

A maximum of 7 grams of this iron-manganese fertilizer can be coated on100 grams of DAP.

C. Coating on DAP (Method II)

The process described in Example 3C was used except that 15 grams of theiron-manganese fertilizer of the example 22 was added to it. The productcontained 1.35 weight percent iron, 0.69 weight percent manganese, 0.77weight percent magnesium, 18.4 weight percent phosphorus and 15.6 weightpercent nitrogen. When the DAP was added to water, the particlesdispersed in about 45 minutes. The coating was firm and did not come offwhen rubbed between the fingers.

Example 25 Calcium Polyphosphate Fertilizer Coated on Urea

The fertilizer of this example was produced from phosphoric acid andcalcium carbonate. Commercial grade phosphoric acid (58.4% P₂O₅), 66grams, was placed in a beaker. In another beaker 50 milliliters of waterwas taken and 25.06 grams calcium carbonate (40% Ca) was added to it toform a slurry. This slurry was added to the phosphoric acid withstirring. It was then heated in an oil bath for 10 minutes till thetemperature of the liquid reached 70° C. At this stage the liquid becamethick. A further 30 milliliters of water was added. It was heated foranother 20 minutes till the liquid temperature reached 103° C.

The sample was removed from the oil bath and allowed to cool to about80° C. Then 14 grams of calcium oxide was suspended in 100 millilitersof water and added to the phosphate liquid with stirring. The productwas poured in a drying dish and dried in an oven at 70° C. After it wasdry, the sample was ground and sieved through a 150 mesh sieve.

On analysis, the product showed 19.12 weight percent phosphorus and 22weight percent calcium. The ratio of equivalents of P:Ca was 0.59:1. ThepH of a 10% suspension in water was 5.56. The number average chainlength of the product was 4.9. Solubility of calcium from this productin water was 1.1% of the total calcium. In 0.1 weight percent citricacid 97% of the total calcium dissolved. In 0.01 N hydrochloric acid 91%of the total calcium dissolved. In 0.005M EDTA, 99% of the total calciumdissolved.

B. Coating on Urea

100 grams of urea was weighed into a dry glass jar and 30 grams of thepolyphosphate fertilizer (of 150 mesh size) was added to it. It wasshaken by hand to mix the contents thoroughly. The zinc fertilizeradhered to the urea and did not sediment at the bottom. The productcontained 5.1 weight percent calcium, 4.4 weight percent phosphorus and35.6 weight percent nitrogen. When the urea was added to water, theparticles immediately dispersed and urea dissolved.

This fertilizer can be coated to the maximum extent of 40 grams forevery 100 grams of urea.

Example 26 Calcium Polyphosphate Fertilizer Coated on DAP A. Productionof Calcium Polyphosphate Fertilizer

The fertilizer of example 25 was used.

B. Coating on DAP (Method II)

The process described in Example 3C was used except that 5 grams ofcalcium polyphosphate of example 25 was used. The calcium polyphosphatefertilizer coated on to the surface of DAP. The coating was firm and didnot come off when rubbed between the fingers. The product contained 1weight percent calcium, 17.96 weight percent phosphorus and 17.1 weightpercent nitrogen. When the product was added to water, the calciumpolyphosphate fertilizer particles dispersed over 30 minutes.

Example 27 Calcium Polyphosphate Fertilizer Granulated A. Production ofCalcium Polyphosphate Fertilizer

The fertilizer of example 1 was used.

B. Granulation (Method I)

100 grams of calcium polyphosphate fertilizer powder (80 mesh) was mixedwith 15 grams of bentonite powder and granulated. The granules were hardand of good quality. The product contained 19.1 weight percent calciumand 16.6 weight percent phosphorus. When the product was added to water,the particles dispersed in 10 minutes. This forms a convenient means ofdelivering the fertilizer.

C. Granulation (Method II)

100 grams of calcium polyphosphate fertilizer powder (80 mesh) was mixedwith water and then granulated. These granules are softer than in methodb above. The product contained 22 weight percent calcium and 19.12weight percent phosphorus. When the product was added to water, theparticles dispersed in 5 minutes. This forms a means of delivering themicronutrient.

Example 28 Calcium-Magnesium Polyphosphate Fertilizer Coated on Urea

The fertilizer of this example was produced from phosphoric acid,calcium carbonate and magnesium oxide. Commercial grade phosphoric acid(58.4% P₂O₅), 83 grams, was placed in a beaker. Then 25.06 grams calciumcarbonate and 8.1 grams magnesium oxide was suspended in 80 millilitersof water and the suspension was added to the phosphoric acid withstirring. Exothermic reaction occurs and the liquid temperature israised to 70° C. It was then heated in an oil bath for 40 minutes tillthe temperature of the liquid reached 107° C. The beaker was removedfrom the heating unit and when the liquid had cooled to about 80° C., asuspension of calcium oxide in water (10.5 g CaO in 20 milliliterswater) was added in a stream with continuous stirring. The product waspoured in a drying dish and dried in an oven at 75° C. After it was dry,the sample was ground in a mortar. It was sieved through a 150 meshsieve.

On analysis, the product showed 19.85 weight percent phosphorus, 16.5weight percent calcium and 4.6 weight percent magnesium. The ratio ofequivalents of Ca+Mg to P was 0.62:1. The pH of a 10% suspension inwater was 4.97. Solubility of calcium from this product in water was0.6% of the total calcium and 4.7% of total magnesium. In 0.1 weightpercent citric acid 98% of the total calcium and 98% of the totalmagnesium dissolved. In 0.01 N hydrochloric acid 97% of the totalcalcium and 98% of total magnesium dissolved. In 0.005M EDTA, 98% of thetotal calcium and magnesium dissolved. XRD for this product showed peaksat 6.8, 5.96, 5.37, 5.01, 47, 4.61, 4.5, 4.15, 3.7, 3.66, 3.58, 3.47,3.39, 3.35, 3.19, 3.13, 3.09, 3.05, 2.96, 2.94, 2.82, 2.76, 2.73, 2.59,2.53, 2.5, 2.43, 2.41, 2.39, 2.37, 2.34, 2.25, 2.2, 2.18, 2.16, 2.14,2.12, 2.09, 2.08, 2.03, 1.99, 1.93, 1.91, 1.85, 1.8, 1.76, 1.72, 1.68,1.64, 1.59 and 1.57 Å.

B. Coating on urea

The process was the same as described in Example 1 except that 50 gramsof the calcium-magnesium polyphosphate fertilizer (of 150 mesh size) ofthis example was added to it. The polyphosphate fertilizer showedexcellent adhesion to urea and did not sediment at the bottom. Theproduct contained 5.5 weight percent calcium, 1.5 weight percentmagnesium, 6.6 weight percent phosphorus and 30.7 weight percentnitrogen. When the urea was added to water, the particles immediatelydispersed and urea dissolved.

This fertilizer can be coated to the maximum extent of 67 grams forevery 100 grams of urea.

Example 29 Calcium-Magnesium Polyphosphate Fertilizer Coated on MAP A.Production of Calcium-Magnesium Polyphosphate Fertilizer

The fertilizer of example 28 was used.

B. Coating on MAP (Method I)

The process described in Example 2B was used except that 5 grams of thecalcium-magnesium polyphosphate fertilizer of the example 28 was addedto it. The product contained 0.78 weight percent calcium, 0.22 weightpercent magnesium, 22.5 weight percent phosphorus and 10.5 weightpercent nitrogen. When the MAP was added to water, the micronutrientfertilizer particles immediately dispersed.

A maximum of 7 grams of this calcium-magnesium polyphosphate fertilizercan be coated on 100 grams of MAP

C. Coating on MAP (Method II)

The process described in Example 2C was used except that 10 grams of thecalcium-magnesium polyphosphate fertilizer of the example 28 was addedto it. The product contained 1.5 weight percent calcium, 0.42 weightpercent magnesium, 22.4 weight percent phosphorus and 10 weight percentnitrogen. When the product was added to water, the particles dispersedin about 30 minutes.

Example 30 Calcium-Magnesium Polyphosphate Fertilizer Granulated A.Production of Calcium-Magnesium Polyphosphate Fertilizer

The fertilizer of example 28 was used.

B. Granulation (Method I)

The process was the same as used in example 27 except thatcalcium-magnesium polyphosphate fertilizer of the example 28 was used.The granules were hard and of good quality. The product contained 14.3weight percent calcium and 17.3 weight percent phosphorus. When theproduct was added to water, the particles dispersed in 10 minutes. Thisforms a convenient means of delivering the fertilizer.

C. Granulation (Method II)

100 grams of calcium polyphosphate fertilizer powder (80 mesh) was mixedwith water and then granulated. These granules are softer than in methodb above. The product contained 16.5 weight percent calcium, 4.6 weightpercent magnesium and 19.8 weight percent phosphorus. When the productwas added to water, the particles dispersed in 5 minutes.

Example 31 Calcium-Magnesium Polyphosphate Fertilizer Coated on Urea

The fertilizer of this example two was produced from phosphoric acid,calcium carbonate and magnesium oxide. Commercial grade phosphoric acid(58.4% P₂O₅), 83 grams, was placed in a beaker. Then 40 grams calciumcarbonate and 8.1 grams magnesium oxide was suspended in 80 millilitersof water and the suspension was added to the phosphoric acid withstirring. Exothermic reaction occurs and the liquid temperature israised to 70° C. It was then heated in an oil bath for 30 minutes tillthe temperature of the liquid reached 103° C. The beaker was removedfrom the heating unit and when the liquid had cooled to about 80° C., asuspension of calcium oxide in water (5 g CaO in 20 milliliters water)was added in a stream with continuous stirring. The product was pouredin a drying dish and dried in an oven at 75° C. After it was dry, thesample was ground in a mortar. It was sieved through a 150 mesh sieve.

On analysis, the product showed 19.46 weight percent phosphorus, 17.6weight percent calcium and 5.14 weight percent magnesium. The ratio ofequivalents of (Ca+Mg) to P was 0.69. The pH of a 10% suspension inwater was 5.1. The number average chain length of the product was 4.5.Solubility of calcium from this product in water was 0.4% of the totalcalcium and 4.9% of total magnesium. In 0.1 weight percent citric acid95% of the total calcium and 96% of the total magnesium dissolved. In0.01 N hydrochloric acid 96% of the total calcium and 98% of totalmagnesium dissolved. In 0.005M EDTA, 96% of the total calcium and 98% oftotal magnesium dissolved.

B. Coating on Urea

The process was the same as described in Example 1 except that 60 gramscalcium-magnesium polyphosphate fertilizer of this example was used. Thecalcium-magnesium polyphosphate fertilizer showed very good adherenceurea and did not sediment at the bottom. The product contained 6.6weight percent calcium, 1.92 weight percent magnesium, 7.3 weightpercent phosphorus and 28.7 weight percent nitrogen. When the urea wasadded to water, the particles immediately dispersed and urea dissolved.

This fertilizer can be coated to the maximum extent of 68 grams forevery 100 grams of urea.

Example 32 Calcium-Magnesium Polyphosphate Fertilizer Coated on DAP A.Production of Calcium-Magnesium Polyphosphate Fertilizer

The fertilizer of example 28 was used.

B. Coating on DAP (Method I)

The process described in Example 3B was used except that 10 grams of thecalcium-magnesium polyphosphate fertilizer of the example 31 was addedto it. The product contained 1.6 weight percent calcium, 0.41 weightpercent magnesium, 18 weight percent phosphorus and 16.4 weight percentnitrogen. When the DAP was added to water, the particles immediatelydispersed.

A maximum of 13.5 grams of this calcium-magnesium polyphosphatefertilizer can be coated on 100 grams of DAP.

C. Coating on DAP (Method II)

The process described in Example 3C was used except that 30 grams of thecalcium-magnesium polyphosphate fertilizer of the example 31 was addedto it. The product contained 4.1 weight percent calcium, 1 weightpercent magnesium, 18.3 weight percent phosphorus and 13.8 weightpercent nitrogen. When the DAP was added to water, the particlesdispersed in about 45 minutes. The coating was firm and did not come offwhen rubbed between the fingers.

Example 33 Calcium-Magnesium Polyphosphate Fertilizer Granulated withUrea A. Production of Calcium-Magnesium Polyphosphate Fertilizer

The fertilizer of example 31 was used.

B. Granulation with urea

100 grams of urea was mixed with 50 grams of the calcium-magnesiumpolyphosphate fertilizer (of 150 mesh size). Water was added to moistenit and it was mixed thoroughly. It was dried at 65° C. The driedgranules of large size were broken and sieved to obtain 2 mm granules.The granules were hard. The product contained 5.9 weight percentcalcium, 1.7 weight percent magnesium, 6.5 weight percent phosphorus and30.7 weight percent nitrogen.

Example 34 Calcium-Magnesium Polyphosphate Fertilizer Granulated withAmmonium Sulfate: Use as a Binding Agent for Ammonium SulfateGranulation C. Production of Calcium-Magnesium Polyphosphate Fertilizer

The fertilizer of example 31 was used.

D. Granulation with Ammonium Sulfate

The process was similar to that described in example 33 except that 20grams of the calcium-magnesium polyphosphate fertilizer of example 31was used. The granules were hard. The product contained 2.9 weightpercent calcium, 0.85 weight percent magnesium, 3.24 weight percentphosphorus, 20 weight percent sulfur and 17.5 weight percent nitrogen.

Example 35 Calcium-Zinc Polyphosphate Fertilizer Coated on Urea

The fertilizer of this example two was produced from phosphoric acid,calcium carbonate (40% Ca) and zinc oxide (80% Zn). Commercial gradephosphoric acid (58.4% P₂O₅), 71.6 grams, was placed in a beaker. Then25.06 grams calcium carbonate and 1.61 grams zinc oxide was suspended in50 milliliters of water and the suspension was added to the phosphoricacid with stirring. It was then heated in an oil bath for 45 minutestill the temperature of the liquid reached 105° C. The beaker wasremoved from the heating unit and allowed to cool to about 70° C. Then asuspension of calcium oxide in water (14.5 grams CaO in 30 milliliterswater) was added in a stream with continuous stirring. At this stage awhite suspension was formed. The product was poured in a drying dish anddried in an oven at 75° C. After it was dry, the sample was ground byhand in a mortar. It was sieved through a 150 mesh sieve.

On analysis, the product showed 18.56 weight percent phosphorus, 20.7weight percent calcium and 1.3 weight percent zinc. The ratio ofequivalents of Ca to P was 0.58:1. The pH of a 10% suspension in waterwas 6.52. Solubility of calcium from this product in water was 0.9% ofthe total calcium and 1% of total magnesium. In 0.1 weight percentcitric acid 99% of the total calcium and 97% of the total zincdissolved. In 0.01 N hydrochloric acid 99% of the total calcium and 98%of the total zinc dissolved. In 0.005M EDTA, 98% of the total calciumand 97% of total zinc dissolved.

B. Coating on Urea

The process was the same as described in example 1 except that 20 gramsof calcium-zinc polyphosphate fertilizer of this example was used. Thezinc fertilizer adhered to the urea and did not sediment at the bottom.The product contained 3.45 weight percent calcium, 0.22 weight percentzinc, 3.1 weight percent phosphorus, and 38.3 weight percent nitrogen.When the urea was added to water, the particles immediately dispersedand urea dissolved. This forms a convenient method of applying the zincfertilizer in the field. It also enriches the urea with micronutrient.

This fertilizer can be coated to the maximum extent of 44 grams forevery 100 grams of urea.

Example 36 Zinc Fertilizer Coated on Urea B. Production of ZincFertilizer

The fertilizer was produced from phosphoric acid (52% P₂O₅) and zinc ash(72% Zn). Commercial grade phosphoric acid (52% P₂O₅), 160 grams, wasplaced in a stainless tray made of SS316L. Then zinc ash was added andstirred to form a slurry. The tray was placed in a muffle furnace andheated at 170° C. for 30 minutes followed by heating at 350° C. for 60minutes till a thick paste was produced. The reacted material wasallowed to cool to room temperature where upon it solidified. It wasmixed with water to form a slurry and 59 milliliters of 25% ammoniasolution was added to it with stirring whereupon a white suspension wasformed. This was mixed well in a blender and dried in a tray drier at80° C. The dried material was powdered in a pulverizer to pass through100 mesh.

The product included 21 weight percent zinc, 5.1 weight percent nitrogenand 19.1 weight percent phosphorous. It had a pH of 4. The ratio ofequivalent of Zn to equivalent of P was 0.347. In 6.9 weight percentcitric acid (0.33M citric acid), 0.005 molar DTPA and 0.1N HCl theproduct released 100 wt % of zinc in 15 minutes. In water 7.5% of totalZn was solubilized. X-ray diffraction diagram for the product shows abroad hump at around 6 Å and peaks at 13.4, 9.21, 7.76, 7.25, 6.71,6.51, 5.98, 5.61, 5.40, 4.79, 4.44, 3.480, 3.327, 3.198, 3.079, 2.998,2.867, 2.797, 2.607, 2.481, 2.344, 2.036 Å.

B. Coating on Urea

5 kilograms grams of urea granules (1-3 mm, 46% N) was weighed into amixer and 250 grams of the zinc fertilizer (of 100 mesh size) was addedto it. It was mixed for 3 minutes and discharged. The zinc fertilizeradhered to the urea and did not sediment at the bottom. The productmainly contained 1 weight percent zinc, 0.91 weight percent phosphorusand 44 weight percent nitrogen. When the urea was added to water, thezinc fertilizer particles immediately dispersed and urea dissolved.

A maximum of 60 grams of this zinc fertilizer can be coated on eachkilogram of urea.

Example 37 Zinc Fertilizer Coated on DAP B. Production of ZincFertilizer

The fertilizer of example 36 was used.

A. Coating on DAP (Method I)

5 kilograms of DAP granules (1-4 mm, 18% N, 17.9% P) was weighed into arapid mixer granulator and its surface was sprayed with about 200milliliters water. Then 550 grams of the zinc fertilizer (of 150 meshsize) was added to it and mixed thoroughly. The mass was discharged anddried with a hot air drier (at 60° C.) with constant mixing of the mass.The zinc fertilizer coated on to the surface of DAP. The coating wasfirm and did not come off when rubbed between the fingers. The productcontained 2 weight percent zinc, 18 weight percent phosphorus and 16.7weight percent nitrogen. When the product was added to water, the zincfertilizer particles dispersed over 35 minutes. This forms a convenientmethod of applying the zinc fertilizer in the field. It also enrichesthe DAP with micronutrient.

Example 38 Zinc Fertilizer Granulated D. Production of Zinc Fertilizer

The fertilizer was produced as described in example 36. Afterneutralization with ammonia the suspension was partially dried to 50 wt% moisture and then transferred into a granulator.

E. Granulation

5 kilograms of moist zinc fertilizer was granulated in a rapid mixergranulator to a size of 1 mm. The granules were then transferred to ahot air drier and dried at 70° C. The granules were hard and wereresistant to breaking between the thumb and first finger. The productcontained 21 weight percent zinc, 19.1 weight percent phosphorus and 5.1weight percent nitrogen. When the product was added to water, theparticles dispersed in 10 minutes. This forms a means of delivering themicronutrient.

Example 39 Molybdenum Fertilizer Coated on Seeds C. Production ofMolybdenum Fertilizer

Phosphoric acid (122 g) containing 60% P₂O₅ was placed in a glass beakerand 7.5 g molybdenum trioxide (MoO₃ containing 66% Mo), 22 g magnesiumoxide (60% Mg) and 11 g sodium carbonate (43% Na) were added to it withstirring. The mixture was poured into stainless steel trays and placedin a muffle furnace at 300° C. After 90 min of heating a solid productwas obtained. It was ground and sieved through a 100 mesh. The productcontained 4.1 wt % molybdenum, 12.7 wt % magnesium, 27.7 wt % phosphorusand 1.8 we/0 sodium. In, 0.1 M HCl, and 0.33 M citric acid more than 98wt % of the total molybdenum dissolved.

D. Coating on Seeds (Soybean Seeds)

1 kilogram of soybean seeds was weighed into a horizontal mixer. In abeaker, 200 milliliters of water was taken and 30 grams bentonite powderwas added to it and stirred. To the bentonite slurry 50 grams of themolybdenum fertilizer (300 mesh) was added and stirred. The slurry wassprayed over the seeds and then dried with an air blower at 40° C. withconstant mixing. The product is soybean seed with 0.2 weightpercentmolybdenum, and 1.4 weight percent phosphorus. When the seedswere placed in water, the fertilizer dispersed immediately. This forms aconvenient method of applying the molybdenum fertilizer in the field. Italso enriches the DAP with micronutrient.

Example 40 Zinc-Iron-Manganese Fertilizer Mixture with NPK Fertilizer C.Production of Zinc-Iron-Manganese Fertilizer

10 kilograms of phosphoric acid (58.5% P₂O₅) was placed in a glassreactor vessel. To the acid, 360 grams of zinc ash (76.8% Zn) was addedwith stirring. The reactor was heated using oil heating at 80° C. for 20min. Then 1.2 kilograms of hematite (46.3% Fe), 560 grams of pyrolusite(49.3% Mn) and 165 grams of magnesia (41.7% Mg) were added and stirred.The suspension was heated with stirring for 200 minutes till the liquidtemperature was 135° C. The liquid was removed from the reactor, allowedto cool to room temperature and neutralized with 10 liters ammoniasolution (25% NH₃). The pH of the product was 5.6. It was then dried ina hot air drier at 80° C., ground in a mortar and sieved through 150mesh BS sieve.

The product included 2.3 wt % zinc, 4.6 wt % iron, 2.2 wt % manganese,0.54 wt % magnesium, 14 wt % nitrogen and 22 wt % phosphorus. In 0.33Mcitric acid the amount of zinc, iron and manganese dissolved was 97 wt%, 95 wt % and 89 wt % respectively of the total zinc, iron andmanganese in the fertilizer. In 0.005M DTPA the amount of zinc, iron,manganese dissolved was 89 wt %, 87 wt % and 85 wt % respectively, ofthe total zinc, iron and manganese in the fertilizer.

D. Mixing with NPK

5 kilograms of urea was taken in a mixer. 500 grams of thezinc-iron-manganese fertilizer of example 40A was added to it. The mixerwas rotated for 4 minutes. The zinc-iron-manganese fertilizer adhered tothe surface of urea. Then 2 kilograms DAP and 1 kilogram muriate ofpotash (potassium chloride) were added and the mixing was done for 5minutes. The micronutrient was distributed uniformly in the mixture anddid not sediment to the bottom. Due to electrostatic adhesion of themicronutrient fertilizer on urea surface it is possible to obtain gooddistribution of micronutrients in a NPK mixture.

C. Coating on DAP

The process described in Example 37 was used except that 1 kilogram ofthe zinc-iron-manganese fertilizer of the example 40 was added to it.The product contained 0.4 wt % zinc, 0.77 weight percent iron, 0.4weight percent manganese, 0.09 weight percent magnesium, 18.7 weightpercent phosphorus and 17.3 weight percent nitrogen. When the DAP wasadded to water, the particles dispersed in about 45 minutes. The coatingwas firm and did not come off when rubbed between the fingers.

1. A population of particles having an average size of greater than 80mesh BS, the particles comprising a water-insoluble, dilute acid-solubleinorganic polyphosphate composition, the inorganic polyphosphatecomposition containing 5 to 70 wt % orthophosphate and having a numberaverage chain length of greater than 2 but less than 50 phosphate unitswhen the orthophosphate content of the polyphosphate polymer is excludedfrom the average chain length calculation and a number average chainlength of at least 1.1 but less than 50 phosphate units when theorthophosphate content of the polyphosphate polymer is included in theaverage chain length calculation.
 2. (canceled)
 3. The population ofparticles of claim 1 wherein the particles have an average size greaterthan 2 mm.
 4. (canceled)
 5. The population of particles of claim 1, thepopulation comprising about 0.1 to 50 wt. % of the water-insoluble,dilute acid-soluble polyphosphate composition. 6-7. (canceled)
 8. Thepopulation of particles of claim 1, the inorganic polyphosphatecomposition containing at least 5 wt. % alkali metal, alkaline earthmetal, ammonium, or a combination thereof. 9-10. (canceled)
 11. Thepopulation of particles of claim 1 wherein the inorganic polyphosphatecomposition contains calcium, magnesium, or a combination thereof, andoptionally one or more micronutrients selected from boron, chromium,cobalt, copper, iodine, iron, manganese, molybdenum, selenium, sulfurand zinc, the inorganic polyphosphate having a ratio, A:P, having avalue of 0.3:1 to 1:1 wherein A is the combined number of equivalents ofcalcium and magnesium incorporated in the inorganic polyphosphatecomposition and P is the number of equivalents of phosphorus, P,incorporated in the inorganic polyphosphate composition.
 12. (canceled)13. The population of particles of claim 1, the inorganic polyphosphatethe inorganic polyphosphate composition containing at least 5 wt. %calcium, magnesium, sodium, potassium or ammonium, in combination, andoptionally, one or more nutrients selected from boron, chromium, cobalt,copper, iodine, iron, manganese, molybdenum, selenium, and zinc, theinorganic polyphosphate composition having a solubility inroom-temperature (25° C.) deionized water such that the combined amountof ammonium, calcium, chromium, cobalt, copper, iron, magnesium,manganese, potassium, selenium, sodium, and zinc that dissolves from theinorganic polyphosphate composition during a 30 minute period indeionized water at room-temperature (25° C.) is less than 20% of thecombined amount of ammonium, calcium, chromium, cobalt, copper, iron,magnesium, manganese, potassium, selenium, sodium, and zinc thatdissolves from the inorganic polyphosphate composition during a 30minute period in 0.1 N HCl at room-temperature (25° C.).
 14. (canceled)15. The population of particles of claim 1, the inorganic polyphosphatecomposition containing at least 5 wt. % of calcium, magnesium, sodium,potassium or ammonium, in combination, and optionally, one or morenutrients selected from boron, chromium, cobalt, copper, iodine, iron,manganese, molybdenum, selenium and zinc, the inorganic polyphosphatecomposition having a solubility in room-temperature (25° C.) dilutecitric acid such that the combined amount of ammonium, calcium,chromium, cobalt, copper, iron, magnesium, manganese, potassium,selenium, sodium, and zinc that dissolves from the inorganicpolyphosphate composition during a 20 minute period in citric acidhaving a citric acid concentration not in excess of 2 wt. % citric acidat room-temperature (25° C.) is at least 75% of the combined amount ofammonium, calcium, chromium, cobalt, copper, iron, magnesium, manganese,potassium, selenium, sodium, and zinc that dissolves from the inorganicpolyphosphate composition during a 20 minute period in 0.1N HCl atroom-temperature (25° C.). 16-17. (canceled)
 18. The population ofparticles of claim 1, the inorganic polyphosphate composition containingat least 5 wt. % of calcium, magnesium, sodium, potassium or ammonium,in combination, and optionally, one or more nutrients selected fromboron, chromium, cobalt, copper, iodine, iron, manganese, molybdenum,selenium and zinc, the inorganic polyphosphate composition having asolubility in room-temperature (25° C.) dilutediethylenetriaminepentaacetic acid (DTPA) such that the combined amountof ammonium, calcium, chromium, cobalt, copper, iron, magnesium,manganese, potassium, selenium, sodium, and zinc that dissolves from theinorganic polyphosphate composition during a 20 minute period in 0.005MDTPA at room-temperature (25° C.) is at least 75% of the combined amountof ammonium, calcium, chromium, cobalt, copper, iron, magnesium,manganese, potassium, selenium, sodium, and zinc that dissolves from theinorganic polyphosphate composition during a 20 minute period in 0.1 NHCl at room-temperature (25° C.). 19-30. (canceled)
 31. The populationof particles of claim 1, wherein the inorganic polyphosphate compositioncomprises one or more micronutrient metal(s) selected from the groupconsisting of chromium, cobalt, copper, iron, manganese, zinc andcombinations thereof with the ratio of the combined number ofequivalents of the micronutrient metal(s), M, to the number ofequivalents of phosphorus, P, in the micronutrient metal polyphosphatecomposition having a value of M:P wherein M:P is less than 0.4:1. 32.The population of particles of claim 1, wherein the repeat unitscomprise phosphate, sulfate, borate, molybdate, or selenate units, or acombination thereof, provided the ratio of phosphate units to thecombined total of sulfate, borate, molybdate and selenate repeat unitscomprised by the inorganic polyphosphate composition is at least 2:1 andwherein the water-insoluble, dilute acid-soluble inorganic polyphosphatecomposition has a ratio, M:Z, that is less than 0.4:1 wherein M is thecombined number of equivalents of the micronutrient metal(s) in thewater-insoluble, dilute acid-soluble inorganic polyphosphate compositionand Z is the combined number of equivalents of phosphorus, sulfur,boron, molybdenum and selenium incorporated into the phosphate, sulfate,borate, molybdate or selenate repeat units. 33-34. (canceled)
 35. Thepopulation of particles of claim 1, wherein the inorganic polyphosphatecomposition contains at least 0.01 wt. % of one or more of boron,chromium, cobalt, copper, iodine, iron, manganese, molybdenum, selenium,sulfur and zinc, the population of particles being a free-flowing powderor granule having a moisture content of less than 10%. 36-37. (canceled)38. The population of particles of claim 1, wherein the inorganicpolyphosphate has a number average chain length of between 2 and 15phosphate units based upon the non-orthophosphate fraction of thepolyphosphate. 39-40. (canceled)
 41. The population of particles ofclaim 1, wherein the inorganic polyphosphate composition contains atleast 7 wt. % but not more than 35 wt. % of calcium and magnesium, incombination.
 42. (canceled)
 43. The population of particles of claim 1,wherein the inorganic polyphosphate composition contains less than 5 wt.% of boron, chromium, cobalt, copper, iodine, iron, manganese,molybdenum, selenium and zinc, in combination.
 44. The population ofparticles of claim 1, wherein the inorganic polyphosphate compositioncontains more than 5 wt. % of boron, chromium, cobalt, copper, iodine,iron, manganese, molybdenum, selenium and zinc, in combination.
 45. Thepopulation of particles of claim 1, wherein the inorganic polyphosphatecomposition contains calcium and magnesium with atomic ratio of calciumto magnesium being at least 0.2:1 (calcium:magnesium).
 46. (canceled)47. A composite particle having a size greater than 0.2 mm, thecomposite particle comprising a water-insoluble, dilute acid-solubleinorganic polyphosphate composition in solid form and a chemicallydistinct composition, the inorganic polyphosphate composition containing5 to 70 wt % orthophosphate, and optionally one or more micronutrientmetals selected from the group consisting of chromium, cobalt, copper,iron, manganese, and zinc, the inorganic polyphosphate polymer has anumber average chain length of greater than 2 and less than 50 repeatunits when the orthophosphate content of the inorganic polyphosphatepolymer is excluded from the average chain length calculation and anumber average chain length of at least 1.1 but less than 50 repeatunits when the orthophosphate content of the inorganic polyphosphatepolymer is included in the average chain length calculation, the repeatunits comprising phosphate, sulfate, borate, molybdate, or selenateunits, or a combination thereof, provided the ratio of phosphate unitsto the combined total of sulfate, borate, molybdate and selenate repeatunits comprised by the inorganic polyphosphate composition is at least2:1.
 48. (canceled)
 49. The composite particle of claim 47 whereincomposite particle comprises an inner layer or core of diluteacid-soluble inorganic polyphosphate composition, and an outer layer ofthe chemically distinct composition.
 50. The composite particle of claim47 wherein composite particle comprises an inner layer or core of thechemically distinct composition and an outer layer of the diluteacid-soluble inorganic polyphosphate composition.
 51. The compositeparticle of claim 47 wherein the chemically distinct composition ismonoammonium phosphate, diammonium phosphate, triple super phosphate, orurea. 52-56. (canceled)